Welcome to the Huberman Lab Podcast,
where we discuss science
and science-based tools for everyday life.
I’m Andrew Huberman,
and I’m a professor of neurobiology and ophthalmology
at Stanford School of Medicine.
This podcast is separate
from my teaching and research roles at Stanford.
It is, however, part of my desire and effort
to bring zero cost to consumer information
about science and science-related tools
to the general public.
In keeping with that theme,
I’d like to thank the sponsors of today’s podcast.
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Athletic Greens is an all-in-one
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I’ve been taking Athletic Greens since 2012,
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The reason I started taking Athletic Greens
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It makes up for any deficiencies that I might have.
In addition, it has probiotics,
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I’ve done a couple of episodes now
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Today’s episode is also brought to us by Thesis.
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Now, to be honest, I am not a fan of the term nootropics.
I don’t believe in smart drugs in the sense that
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I’m pleased to announce that the Huberman Lab Podcast
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We are now beginning a new topic
for the next four to five episodes
of the Huberman Lab Podcast.
Before we move into that,
I want to just briefly touch on a couple of questions
that I got from the last episode,
which was related to the science of endurance training.
I described the four kinds of endurance training.
We posted protocols of the specific four kinds
of endurance training at hubermanlab.com.
Just go to that episode.
You can see the download.
It’s a zero-cost PDF.
I got a lot of questions
about what’s called concurrent training,
which is how to program endurance training
if you are also interested
in strength and hypertrophy training,
or how to incorporate strength and hypertrophy training,
which was in the previous episode, with endurance training.
This can all be made very simple.
Ask yourself, what are you trying to emphasize?
And then emphasize that for a 10 to 12-week cycle.
So if you’re mostly interested in endurance,
I would say use a three-to-two ratio.
Maybe get three endurance training workouts per week,
maybe four, and two strength and hypertrophy workouts.
If you’re mainly focusing on strength and hypertrophy,
get three or four workouts for strength and hypertrophy,
and do two endurance workouts.
Start with the minimum number of sets that’s required
to get the result that you want.
So if you’re not accustomed to doing endurance work,
you would start with the minimum number
that’s listed on that protocol.
So if it says three to five sets,
you would start with three, maybe even just two,
and then work your way up by adding sets each week.
I do suggest that people get
at least one complete rest day per week,
although I know a lot of people don’t like that.
I benefit from that.
I actually benefit from having
two complete rest days each week.
I just continue to make progress that way,
whether or not it’s for strength and hypertrophy
or for endurance.
I am a big believer in rest days.
Other people are not.
And those can be active rest days,
hiking, relaxing, et cetera.
After a 10 to 12-week cycle,
then I also suggest taking anywhere
from five to seven days completely off.
You can still enjoy life and do things.
I know for you addicted exercisers
that you’re going to loathe to do that,
but that’s one way to stay injury-free,
keep your joints and tissues healthy over time,
and continue to make progress.
If you don’t want to do that week off, don’t do it.
None of this is holy.
None of it is a strict prescriptive.
Just ask yourself, what are you going to emphasize
and emphasize that in terms of the total volume
of workouts that you do and work up incrementally
and then move into another cycle?
That’s what I suggest.
So go to hubermanlab.com.
You can get the protocol there.
We are now going to move into a new topic
unrelated to physical performance,
starting with this episode.
And for the next four to five episodes,
we are going to talk all about the senses.
That’s sight, eyesight, hearing, touch, taste, smell.
And we are also going to talk about this critical sense
that we call interoception,
or our sense of our internal real estate.
Now, the reason that we are talking about the senses
is because if you understand how the senses are perceived,
what they’re about,
what the underlying cells and connections are about,
you will be in a terrific position to understand
the month’s topic that follows,
which is all about mental health.
Now, I want to emphasize that if you’re somebody
who doesn’t have any trouble seeing, hearing,
and has an excellent sense of interoception,
I do believe that these episodes
will still be very relevant to you
because they have everything to do with
how you move through the world,
how you make sense of information,
and how you organize your thoughts and your emotions.
I also want to emphasize that we’re going to cover
a lot of practical tools.
So today’s episode is going to be all about vision
and eyesight, a topic that’s very near and dear to my heart
because it’s the one that I’ve been focusing on
for well over 25 years of my career.
But we’re not just going to get into the mechanistic details
about how light is converted into electrical potentials
and things like that.
We are going to talk about practical tools
that you can and should use to help maintain the health
of your visual system and your eyesight.
Very often, young people will say, what should I do?
You know, you’re always talking about, you know,
neuroplasticity and how it tapers off over time,
but I’m a young person, what should I do?
You should absolutely train and support your eyesight.
In fact, if you’re a young person and you see perfectly
or you feel as if you see the world perfectly,
you are in the best position to bolster,
to reinforce that visual system
so that you don’t lose your vision as you age.
In addition, you can leverage your visual system
for better mental and physical performance,
and we’re going to talk about that.
If you’re somebody who suffers from a clinical disorder
of vision, you have trouble seeing,
or if you need corrective lenses in order to see,
this episode is definitely for you.
And while, of course, I can’t make clinical diagnoses,
I can’t have a one-on-one conversation
with any of you in this format, nor am I a clinician,
I’m a scientist, not a physician,
I did consult with our chair of ophthalmology,
Dr. Jeffrey Goldberg
at Stanford University School of Medicine,
as well as several other people
to really vet the information
and make sure that the protocols that I’m describing
are consistent with the clinical literature.
If you have a severe eye problem,
you should be working with a really good ophthalmologist
and or optometrist,
but certainly an ophthalmologist who’s a medical doctor.
But I do believe that the information
that we’re going to discuss today
is going to be relevant to everybody,
and we’ll set the stage for the month on mental health
and mental performance.
So let’s get started.
When we hear the word vision,
we most often think about eyesight,
or our ability to perceive shapes and objects
and faces and colors.
And indeed, vision involves eyesight,
our ability to see shapes and objects
and faces and colors and so forth.
However, our eyes are responsible for much more than that,
including our mood, our level of alertness,
and all of that is included in what we call vision.
So I just want to take about three, maybe four minutes
and talk about how the visual system works,
how it’s built, and how you are able
to so-called see things around you.
I also want to describe the ways in which your eyes
and your visual system impact your mood
and your level of alertness.
And then we are going to get right into some protocols,
some specific things that each and all of you should do
if you want to enhance your vision
and maintain your vision as you get older.
And again, if you’re a 15-year-old or a 12-year-old,
this episode is especially for you
because your nervous system is far more plastic
than mine is.
It’s much more amenable to change.
So you can really build a very strong visual system.
And in doing that, and if you adopt specific behaviors
at any age of light viewing at particular times
in particular ways, then you can build an emotional system
that’s also reinforced by your visual system.
So let’s talk about vision.
What is vision?
Well, vision starts with the eyes.
We have no what’s called extraocular light perception.
While it feels good to have light on our skin,
while it feels good to be outside in the sunlight
for most people, the only way that light information
can get to the cells of your body
is through these two little goodies
on the front of your face.
And for those of you listening, I’m just pointing to my eyes.
As many of you have heard me say before
on this and other podcasts,
your eyes in particular, your neural retinas
are part of your central nervous system.
They are part of your brain.
They’re the only part of your brain
that sits outside the cranial vault.
In other words, you have two pieces of your brain
that deliberately got squeezed out of the skull
during development and placed in these things
we call eye sockets.
There’s a genetic program for the specific purpose
of making sure that three little layers of neurons,
nerve cells got squeezed out
and form what are called your neural retinas.
Now the eyes have a lot of other goodies in them
that are very important.
And those are the goodies that we’re going to focus on
a lot today.
There’s a lens to focus light precisely to the retina.
If you’re somebody who requires eyeglasses or contacts,
chances are you don’t do that correctly.
And so that’s why you use other lenses
like eyeglasses or contacts.
There are also other pieces of the eye
that are designed to keep the eye lubricated.
You also have these things that we call eyelashes.
Most people don’t know this,
but eyelashes are there to trigger the blink reflex
if a piece of dust or something gets in front of your eye.
It’s a beautiful adaptation of nature.
They aren’t just aesthetically nice.
Costello happens to have very long eyelashes.
He gets compliments about this all the time.
Maybe you have long eyelashes.
I don’t have particularly long eyelashes,
but the eyelashes are there
so that if a piece of dust or something
starts to head towards the cornea,
the eye blinks very, very fast.
It’s the fastest reflex you own is your eye blink reflex.
We also have these things called eyelids.
Now eyelids might seem like the most boring topic of all,
but they are incredibly fascinating.
Today, we’re going to talk about
how you can actually use your visual system
to increase your levels of alertness
based on the neural circuits
that link your brainstem with your eyelids.
And no, we are not going to have a blinking contest
because I would win and you would lose,
and that wouldn’t be fun for you.
So let’s talk about what the eyes do for vision.
Basically, the entire job of the eyes
is to collect light information
and send it off to the rest of the brain
in a form that the brain can understand.
Remember, no light actually gets in
past those neural retinas.
It gets to the neural retina,
and we have specific cells in the eye called photoreceptors.
They come in two different types, rods and cones.
Cones are mainly responsible for daytime vision,
and the rods are mainly responsible for vision at night
or under low light conditions, generally speaking.
So basically what happens is if your eyelids are open,
light comes into the eye.
The lens focuses that light.
Light is also just called photons,
light energy, onto the retina.
These photoreceptors, the rods and cones,
have chemical reactions inside them
that involve things like vitamin A,
and that chemical reaction converts the light
Now, that might seem incredibly abstract,
but the way to think about this is very similar to,
for instance, you have touch receptors on your skin,
and when you press on those touch receptors,
they convert pressure, physical pressure,
into electrical information,
and those neurons send it up to your spinal cord and brain.
You can register that somebody or you are touching
the top of your hand as I’m doing now.
With the eyes and the retina,
it’s just that light gets converted
into electrical information.
Within the eye, within the retina,
there are then a series of stages of processing,
and that information eventually gets sent into the brain
by a very specific class of neurons.
I would like you to know the names of these neurons.
They’re called retinal ganglion cells.
So the only thing you need to know
about the neuroscience of the eye at this point
are that there are rods and cones.
The cones are involved in bright daytime vision,
and rods are involved in more dusk or nighttime vision,
and you’ve got these cells called retinal ganglion cells
that send the information off to the rest of the brain.
Now, here’s what’s incredible.
I just want you to ponder this for a second.
This still blows my mind.
Everything you see around you,
you’re not actually seeing those objects directly.
What you’re doing is you’re making a best guess
about what’s there based on the pattern of electricity
that arrives in your brain.
Now, that might just seem totally wild
and hard to wrap your head around,
but think about it this way,
because this is the way it actually works.
Let’s take an example of a color, like green or blue.
You have cones in your eye that respond best
to the wavelength of light
that is reflected off, say, a green apple.
So you don’t actually see the green apple.
What you see is the light bouncing off that green apple,
and it goes into your eye,
and you see it and perceive it as round and green,
but not because you see anything green.
No green light arrives in your brain.
What happens is your brain actually compares
the amount of green reflection coming off that apple
to the amount of red and blue around it.
Well, you might say, well,
the green apple is sitting on a brown table
or a white surface.
Well, then it will appear very green
because the amount of wavelength of light for green
is very high, and the amount for red is very low,
and so it looks very green, okay?
So we don’t actually see anything directly.
What the brain is receiving is a series of signals,
electrical signals, and it’s comparing electrical signals
in order to come up with what we call these perceptions,
like I see something green, a green apple, or I see red.
Let me give you a slightly different example.
If you were to play a key on the piano,
let’s say you play, I’m not a musician,
so hopefully I won’t get this too incorrectly,
but let’s say you have like E sharp,
and maybe it’s on ding, ding, ding, ding, ding.
If the brain gets that signal, it doesn’t actually know E.
That’s what, it doesn’t recognize it
until you were to play another key next to it,
dun, dun, dun, dun, dun,
and what it does is it does the math,
it does the subtraction, and it compares those two.
So when we see something green, or we see something red,
or we see something blue,
we’re not actually seeing it directly.
The brain is making a guess
about how green, or red, or blue that thing is
by comparing what’s around it, okay?
And if that seems hard to wrap your head around, don’t worry
because we will explain it in more depth going forward,
but I really want people to understand this,
that vision, eyesight, is not looking at things directly
and that information getting directly into your brain.
It is translated.
Light information is transformed into electrical signals
that your visual system exquisitely understands.
Now, what does this mean?
Why should you care about this?
Well, if you have a dog like I do, or a cat,
they are not colorblind,
but they lack the cones that respond to red,
meaning long wavelength light.
So what does that mean?
That means that when they see green,
it’s different than the green you see,
not because that apple isn’t visible to them,
but because they aren’t able to compare it to red,
and you are.
As a consequence, when they look at a green lawn,
it looks more brownish or orange to them.
When you wear a red shirt in front of your dog or cat,
if you see a stop sign and they see a stop sign,
they see orangish brown and you see red,
presuming that you are a trichromat,
meaning you have three color vision.
So this is all to say that every animal
sees the world differently,
depending on whether or not they have one or two
or three of these different cones,
the red, blue, or green cones.
If you are a mantis shrimp of all things,
you see hundreds of colors that human beings can’t see.
Many animals see into visual ranges
that you and I can’t see in.
So for instance, a pit viper senses heat emissions.
It literally sees the heat coming off of you
or of an animal that they want to eat.
If you are a ground squirrel, you can see ultraviolet light.
This is going to sound kind of weird,
but ground squirrels actually signal one another
by standing up outside and shining sunlight
off each other’s stomachs to each other,
signaling at a distance, just like, you know,
you could signal somebody with a mirror
and sunlight at distance.
There are species of primates,
this isn’t very pleasant to think about,
that urinate on their hands
and then wipe it all over their stomach
and then use that sunlight
to reflect different signals to each other.
I don’t know what they’re saying.
We always assume it’s something cute and nice,
but maybe they’re insulting each other.
So this actually gets right down to the heart
of these bigger questions like consciousness.
What do we see?
What’s out there?
How much of life is really accessible to us?
And I could go on and on.
You know, this used to be kind of an obsession of mine
when I was coming up in the field of visual neuroscience
to understand how different animals
see the world compared to us.
I’ll give one more example, a diving bird,
you know, a bird that flies over the ocean.
It has an incredible task.
It has to both view the horizon
and it has to view schools of fish.
And then it has to make a trajectory down into the water
and grab one of those fish to eat.
And the water has what’s called a refractory index.
It actually shifts like a prism,
the impression or the perception
of where that fish is, right?
If the bird sees the fish right below it,
it has to know, it has to adjust its diving trajectory
just right because it knows that that fish
actually isn’t where it sees it.
It’s probably a few inches ahead or to the side of that
because of the way that water diverts the image.
If you’ve ever dropped a coin to the bottom of a pool,
if you go straight down looking at that location,
if you were to look from the top of the pool
and you dive straight down with your eyes closed,
you will miss because the water refracts,
it shifts the visual image.
Well, diving birds have an arrangement
of these retinal cells that communicate to the brain.
That’s both a streak to view the horizon
because they need to know where they are
relative to the horizon.
And they have a pupil like we do on the bottom of their eye
so that they can make very accurate dive
and attacks on these schools of fish
and catch fish and eat those fish.
We just have pupils in the middle of our eyes.
So there’s a ton about the optics of the eye
and the way that it communicates with the brain
that allows us to see.
We could spend hours talking about this,
but what I’d like to embed in your mind
is that what you experience in the outside world
It’s limited by which wavelengths, which colors,
if you will, of light that you can see,
that your brain is coming up with a best guess
about what’s there.
It doesn’t actually know what’s there
and that your vision is distinctly different
from say the vision of a dog
or from the vision of somebody who’s a dichromat,
meaning they don’t have a red cone.
A lot of people in particular, about one in 80 males
lacks a red cone and therefore sees the world
much the same way that Costello does,
although he sees it from just much lower toward the ground.
So that’s what I’d like you to understand
about the way the eye communicates with the brain.
I would also like you to understand
that the brain itself is making these guesses
and that those guesses are largely right.
How do I know that?
Well, they’re right because when you reach out
to grab a glass, most of the time you grab the glass
and you don’t miss, right?
Most of the time when you make judgments
about the world around you
based on your visual impression of them,
it allows you to move functionally through the world.
But let me give you some examples
of where this guessing is happening right now.
And it’s so incredible that to this day,
this still blows my mind.
Cover one eye with one hand.
If you’re driving, maybe don’t do this.
If you’re viewing the world around you,
presumably you can see everything that’s out there.
I could do this with one eye or the other eye.
You probably see better out of one or the other
and we’ll talk about that.
You have a giant blind spot
in the middle of your visual field.
It’s called your blind spot.
It is the spot in which the connections,
the wires from all those retinal ganglion cells
exit the back of the eye and head off toward the brain.
In other words, you are blind for a huge spot
of your central vision, the part of your vision
that’s highest acuity, highest detail.
And yet you don’t see that ever.
You cover one eye and you see perfectly fine.
And it’s not just because your eye
is moving around really quickly.
Your brain is guessing what’s in that spot,
which is absolutely incredible.
And so you don’t see that blind spot.
This is happening all the time.
Now, when you have two eyes open,
the way that your eyes are positioned in your head
and the way they view the world is such
that they fill in each other’s blind spot.
So it’s pretty convenient.
But if you cover one eye, that’s impossible.
And yet you still see the world as complete.
So the brain is doing these incredible things.
It’s also creating depth, a sense of depth,
even though what arrives from the retina
is essentially a readout of a two-dimensional flat image.
So it can sense depth.
How do you know depth?
Well, this is very simple.
Things that are closer to you tend to be larger
than things that are far away.
Things that are closer to you tend to look
like they’re moving faster.
If you’ve ever been in a train and you look to your side,
the rungs on a fence or the train tracks going by you
look like they’re going very fast.
If you look off in the distance,
they look like they’re moving very slowly.
And there are differences between what’s close to you
and what’s further away.
So a little house on the horizon,
you don’t look at it and say,
oh, that must be a tiny little house.
You have some prior knowledge
that things further away are smaller.
So that’s the main way that you do that.
And you compare the location
at which information about light lands on the two eyes.
So your eyes are slightly offset from one another.
So that, for instance, if I look at you,
if you were standing right in front of me right now
and I were to look at you, the image of your face,
the light bouncing off your face, to be more precise,
lands on one eye in a slightly different location
than it does in the other eye.
And then the brain does math.
It basically does the equivalent of geometry
and trigonometry and essentially figures out
how far away you are from me, which is just incredible.
So the brain does all this very, very fast.
And the brain uses about 40 to 50%
of its total real estate for vision.
That’s how important vision is.
Now, for those of you that are blind
or low vision or no vision,
that real estate in the brain will be taken over
by neurons that control a sense of touch
and a sense of hearing.
And indeed, hearing and touch are much better,
higher acuity and faster in blind people.
But for most of you who I presume are sighted,
this is how it works.
So that’s kind of vision from eye to brain in a nutshell.
There are a bunch of different stations in the brain
that do different things.
Now I want to talk about the other aspect of vision,
which is the stuff that you don’t perceive,
the subconscious stuff.
And then we’ll transition directly
into how you can use light and eyesight
to control this other stuff,
because it’s very important.
And that other stuff is mood, sleep, and appetite.
And there are ways in which you can use
the same protocols that I will describe
in order to preserve and even enhance your vision,
your ability to see things and consciously perceive them.
So the protocols we will describe
have a lot of carry over to both conscious eyesight
and to these subconscious aspects of vision.
And I just want you to understand a little bit more
about the science of seeing, of eyesight and vision,
and then all the protocols will make perfect sense.
So as amazing as eyesight is,
it actually did not evolve for us to see shapes
and colors and motion and form.
The most ancient cells in our eyes
and the reason we have eyes
is to communicate information about time of day
to the rest of the brain and body.
Remember, there’s no extraocular photoreception.
There’s no way for light information
to get to all the cells of your body,
but every cell in your body needs to know
if it’s night or day.
I talked a little bit about this in the episodes on sleep.
And this episode is not about sleep,
but I want to emphasize that there is a particular category
of retinal ganglion cell.
Remember the neurons that connect the retina to the brain
that is involved in a special kind of vision
that has nothing to do with conscious perception
of what’s around you.
And it’s happening right now.
It’s happening all the time.
These are so-called melanopsin retinal ganglion cells
named after the opsin that they contain within them.
They are essentially photoreceptors.
Remember before I said there are photoreceptors
and then these ganglion cells?
Well, these melanopsin cells, as the name suggests,
melanopsin have their own photoreceptor built inside them.
The opsin that they contain is actually very similar
to the melanopsin that is present in the skin
of some amphibians and that causes those amphibians
to change their skin color in different light conditions.
So you have, believe it or not,
a little bit of frog skin in your eye, so to speak.
Okay, not exactly, but you essentially have the equivalent
of what frogs have in their skin in your eye.
If you are low vision or no vision,
as long as you have retinas,
it’s very likely you still have these cells
even though you can’t see or you don’t see well.
These cells, retinal ganglion cells,
communicate to areas of the brain
when particular qualities of light
are present in your environment
and signal to the brain, therefore,
that it’s early day or late in the day.
These melanopsin ganglion cells
are sometimes also called intrinsically photosensitive cells
because they behave like photoreceptors.
What do these cells respond to
and why should you care about them?
Well, you should care about them
because they regulate when you’ll get sleepy,
when you’ll feel awake,
how fast your metabolism is, excuse me,
your blood sugar levels, your dopamine levels,
and your pain threshold.
There are other factors that impact those things,
but they are one of the, if not the most powerful determinant
of those other things like mood and pain threshold,
sleepiness, wakefulness, et cetera.
These melanopsin ganglion cells have been shown
by the NITES group, N-E-I-T-E-S,
up at the University of Washington
and by Samer Hattar’s lab and David Bersin’s lab
and a number of other people’s labs,
such in Panda, Iggy Provencio, et cetera,
a number of excellent labs in neuroscience
to set the circadian clock and to respond best
to the contrast between blue and yellow light
of the sort that lands on these cells
when you view the sun,
when it’s at so-called low solar angle,
when it’s low in the sky,
either in the morning or in the evening.
What does all this mean?
It means, and here’s the first protocol,
and you’ve probably heard me say this before,
but it is appropriate to this episode to say it again.
If you are not viewing the sun, sunlight,
even through cloud cover for two to 10 minutes
in the early part of the day
when the sun is still low in the sky
and doing the same thing again in the evening,
you are severely disrupting your sleep rhythms,
your mood, your hormones, your metabolism,
your pain threshold, and many other factors,
including your ability to learn and remember information.
The most central and important aspect of our biology
and perhaps our psychology as well
is to anchor ourselves in time,
to know when we exist, okay?
It sounds a little bit abstract and philosophical,
but it’s not.
And we don’t know time as a real thing
because of watches and clocks.
We know time at a biological level
based on where the sun is and where,
which of course is where we are relative to the sun
because the earth is spinning around.
Now, what does this mean for a protocol?
It means see, get that light in your eyes early in the day
and anytime you want to be awake.
So try and get as much sunlight in your eyes
during the day as you safely can.
We’ll talk about eye safety this episode in depth.
And the blue light and the contrast of that blue yellow,
remember, we don’t see blue.
This is all subconscious.
This is blue reflections coming off of sunlight.
Blue light, we’ve been told is so terrible for us.
It is absolutely essential and wonderful
for waking up the brain,
for triggering all sorts of positive biological reactions,
but it needs to be viewed early in the day.
If you can’t see sunlight
because it’s the thick cloud cover of say in a,
you know, you’re in the UK and it’s winter,
then artificial lights,
especially blue lights would be very beneficial to you.
You need a lot of this light and its contrast with yellow
in order to trigger these melanopsin cells,
which would then trigger your circadian clock,
which sits above the roof of your mouth,
which will signal every cell in your body,
including temperature rhythms, et cetera.
So first things first,
your visual system was not for seeing faces, motion,
The most ancient cells in your eye,
which are there right now as we speak,
are there to inform your body and brain about time of day.
So you want to get that bright light early in the day.
Absolutely essential, two to 10 minutes.
You can download the light meter app
if you want to measure lux.
When I explained how to do that in earlier episodes,
it got a little convoluted.
Get that two to 10 minutes, ideally without sunglasses.
Now, here’s another reason to do this,
and I’ve never spoken about this before on any podcast,
which is that there have been several studies now
in thousands of subjects exploring what can be done
to prevent myopia, nearsightedness, and other visual defects.
And it turns out in a series of large clinical trials,
the conclusion has emerged that getting two hours a day
of outdoor time without sunglasses, blue light,
this blue light that everyone has demonized,
getting that sunlight during the day for two hours,
even if you’re reading other things
and doing other things outside,
has a significant effect on reducing the probability
that you will get myopia, nearsightedness.
Now, whether or not that’s also due to the fact
that myopia can be caused by viewing things
up close too much.
So if you’re indoors,
we tend to be looking at things more closely, right?
Unless you have a very large house
with walls that are very far away from you.
But the effect does seem to be directly related
to getting sunlight and not just to the distance
that you’re viewing.
I’m going to describe this study just briefly,
but this is a second protocol.
So we have one protocol about getting sunlight
to set your circadian clocks, meaning wake you up,
establish your sleep,
will occur about 12 to 16 hours later.
That’s all in the sleep episode,
but also to enhance your mood, to enhance your metabolism,
to optimize your hormone levels,
and to optimize learning and dopamine levels,
this feel good neuromodulator that’s essential
to not getting depressed, et cetera.
But now there’s a second protocol, which is ideally,
and this includes children,
as long as they’re not very small infants,
ideally, we’re all getting two hours of outdoor time,
even if there’s cloud cover.
Remember, we evolved mostly under outdoor conditions,
not indoor conditions.
And no artificial blue light will not replace this aspect
of your visual system and offsetting myopia.
So I just want to briefly describe this study
because it’s a very important one,
and I don’t think it’s discussed often enough.
There are many studies exploring this,
but one of the ones I like the most looked at 693 students,
and a subset of them were encouraged
to spend 11 hours a week outdoors, okay?
So most kids are in school five days a week or so.
So they’re spending 11 hours a week outdoors.
They are sometimes reading outdoors.
They’re not always just playing outdoors.
They might be reading books, et cetera.
They used eight different schools.
And the reason they did this study,
I probably should have mentioned,
is that myopia, nearsightedness, is a global epidemic.
At least that’s how it was referred to in the study.
I don’t know who decides what’s an epidemic or not.
I think there are thresholds for that.
This paper published in the journal,
Ophthalmology in 2018,
described the fact that being outdoors for two hours a day
could significantly reduce the probability
that these children would develop nearsightedness.
And it turns out, based on other studies,
that adults who spend two hours a day outside,
so that would be reading outside, talking outside,
no, it does not include light
coming through the windshield of your car.
I’ll explain why in a few moments.
Offset the formation of myopia.
Now, myopia or nearsightedness has to do
with the way that the lens focuses light onto the retina.
I don’t want to get into a long description of this now,
but basically the lens has to bring light to the retina,
not in front of it, not behind it.
If it brings light to a position in front of the retina,
then you won’t see clearly.
You will need corrective lenses.
If it brings light directly to the retina,
then you will see clearly.
That should be intuitive why that makes sense.
So you might say, why would being outside,
getting this blue light or this blue-yellow contrast
from sunlight actually offset myopia?
Well, it probably, and I want to emphasize probably,
has to do with the fact
that these melanopsin ganglion cells,
these intrinsically photosensitive ganglion cells
are not just responsible for sleep
and talking to your circadian clock and that sort of thing.
They also make connections within the retina.
They connect to things like, this is for the aficionados,
the ciliary body, the iris, the muscles,
and the structures within the eye
that actually move the lens
and allow you to adjust your vision
to things up close or far away.
And in doing so, they increase or improve the health
of the little tiny muscles within the eye
that move the lens.
And they probably, again,
this needs a little bit more work
in order to really tamp down the mechanism.
They’re probably also involved in bringing growth factors
and blood supply to the muscles and to the neurons
that are responsible
for this focusing mechanism within the eye.
So remember, your eye is an optical device.
You were born with lenses.
You don’t have to use glasses, or maybe you do,
because you have lenses in your eyes.
And those lenses need to move.
It’s not a rigid lens like a glass lens.
It’s a dynamic lens.
It has little muscles that pull on it and squeeze it.
And make it thicker or thinner
as you look at things close and far away.
And I’ll describe how that works in a moment.
These melanopsin cells and their activation by sunlight,
completely subconsciously, you’re unaware of this,
promote the health of this system within the eye
and allow you to offset the myopia, nearsightedness.
In other words, getting outside for two hours a day,
each day, on average, even if there’s cloud cover,
without sunglasses on,
will allow you to offset the formation of myopia.
Now, you might still form myopia
if you have certain structural features
or genetic basis for that.
We will talk about things that you can do as well.
But for everybody, we should be doing this.
And that might seem like a lot,
but this is the way that your visual system works.
Staying indoors, just getting artificial light,
and looking at things up close,
leads to visual defects, okay?
It’s a form of kind of like visual obesity, right?
The posture of your visual system, if you will,
is going to be unhealthy if you’re just indoors
and you’re not getting sunlight early in the day
and for at least two hours per day.
I want to talk a little bit more about how our eyes adjust
to things that are close to us or far away.
This is an absolutely brilliant consequence
of our nature and our design.
And whenever I say nature and design,
people always ask me, you know,
what are you really trying to say?
Are you trying to talk about creators?
Are you talking about intelligent design?
Look, I want to be very frank with you.
I wasn’t consulted at the design phase and neither were you.
And so that is all very interesting,
but it’s not the topic of this discussion.
What is clear and what is the topic of this discussion
is that the eye can dynamically adjust where light lands
by moving the lens and changing the shape of the lens
in your eye through a process called accommodation.
And if you understand this process of accommodation,
you not only can enhance the health of your eyes
in the immediate and long-term, but you also can work better.
You’ll be able to focus better on physical and mental work.
You will be able to concentrate for longer.
And I want to emphasize that so much of our mental focus,
whether or not it’s for cognitive endeavors
or physical endeavors,
is grounded in where we place our visual focus.
Okay, what we look at and our ability
to hold our concentration there
is critically determining how we think.
So in other words, if you can hold visual focus,
you can hold mental focus, cognitive focus,
but holding visual focus is challenging.
It’s tiring because it requires movement of the lens.
And that movement of the lens requires activation
of muscles and the activation of muscles,
as you know, from the physical performance episodes,
if you saw them, and even if you don’t,
is dictated by neurons.
So what is accommodation?
Well, it’s actually very simple and very elegant.
And again, this is another case
where whenever I look at this stuff,
even though I’ve been looking at it for years,
learning about it for years,
it still boggles my mind that we have these apparati
built into our eyes.
So we have lenses in our eyes
and we have these things called the irises.
You’re all familiar with the iris
because you’ll see people’s pupils get bigger or smaller.
And we intuitively think of eyes as having the pupils.
If you actually draw two circles on a sheet of paper
and they look like two circles,
but if you put little dots in the middle of them,
they look like eyes.
Your brain recognizes those as eyes
because one of the first things you see
when you come into this world are eyes.
And actually, if you put the little dots close together,
it’ll look kind of wrong, like it’s cross-eyed.
And if you put them at different locations
within those two dots, opposing locations,
it’ll look Google-eyed.
And so your brain is actually filling in all the face
and other information, even emotional information,
just based on this recognition of eyes.
And so there’s clearly, we know this,
there’s real estate deep up, further up in the brain
that’s responsible for analyzing and recognizing faces.
And the eyes and the position of these little things
we call irises and pupils, et cetera,
is really important for how we interpret
the status of others.
And that’s why it’s such a powerful thing
just to put two circles and move the pupils around on paper.
In fact, I want to get into a combination,
but if you think about it,
if one of my pupils was up there
and the other one was down there,
one was really big and one was really small,
that would actually be a sign of pretty severe damage.
If someone gets hit hard on the side of the head,
you’ll notice that they shine a light in one eye.
You know what they’re doing that?
They’re actually looking at the other eye.
When you shine light of the eye,
that pupil constricts to limit the amount of light
that comes in so it doesn’t damage the eye.
This also happens when you walk outside and it’s bright.
It constricts, but we have what’s called
the consensual pupil reflex.
There’s a connection deep in the brainstem,
deep back here in the brain near my neck
that connects the pupil mechanism for the two eyes.
And they’re looking at the other eye.
And if you shine light in one eye
and that pupil constricts, but the other one doesn’t,
there’s a good chance there’s brainstem damage.
This is what they do on the side of a football field
or a boxing match, or if someone,
unfortunately, hits their head.
So two pupils, and don’t freak out
if one pupil is a little bit smaller than the other,
that doesn’t necessarily mean brain damage.
But if you suddenly have one pupil bigger than the other,
you absolutely want to go see a neurologist right away.
So the eyes and the pupils are indicative
of things that are happening deep in the brain.
Now, accommodation is our ability to accommodate
to things that are up close here or further away.
And the way this works is that the iris
and the musculature in a structure
called the ciliary body move the lens.
So when you look far away, okay,
when you see things far away,
your lens actually relaxes, it can flatten out.
So I want you to think about this.
When you look far away, when it may be anywhere
from like 20 feet away from you out to a horizon
that’s miles or kilometers away from you,
the lens can just relax, it can flatten out.
And you’ll notice that it actually is relaxing
to look at a horizon.
It’s relaxing to look far away.
Whereas if I look at something up close to me,
like this pen or my phone or a computer screen
or this microphone, it takes effort.
You’ll sense the effort.
Now, some of that effort is actually eye movements
because you have muscles that can move your eyes
within their sockets.
But a lot of the work, quote unquote, is neural work
of the muscles having to move and contract
such that the lens actually gets thicker
in order to bring the light to the retina
and not to a location in front of it or behind it,
There’s also changes in the size of the pupil
as things are closer and further away from you.
In fact, there’s a simple way to think about this.
Healthy pupils are going to dilate
when you look at something far away from you.
Now, when you see something that excites you
or stresses you out, your pupils also get big.
Your eyes get wide.
But if you look at something far away,
your pupils are going to dilate.
And when you look at things that are closer to you,
when you move them up close,
the pupils are going to shrink.
That’s all part of this accommodation mechanism.
Now, you might say,
why are you telling me about accommodation?
This is crazy.
Why are you telling me about this?
Well, these days we’re spending a lot of time
looking at things, mainly our phones up close
and computers up close, and we are indoors.
If you are a young person,
and even if you are 25 or older,
and you are spending a lot of time
looking at things up close,
and you are not allowing your vision to relax,
in other words, you are not giving your lens
the opportunity to flatten out
and for these muscles to relieve themselves of this work,
you may or may not have migraine headaches.
You may or may not have headaches.
You might, and that could be the cause of those.
But you are also training your eyes
to be good at looking at things up close and not far away,
and as a consequence,
you are reshaping the neural circuitry in your brain,
and it is not good, it is not healthy
to only look at things up close.
Now, there are a lot of recommendations out there right now,
especially with all the lockdowns of the last 12 to 18 months
that people should look up from Zoom every once in a while,
or maybe now I’m hearing that people should take calls
instead of doing Zoom,
or you should look up from your computer screen.
It’s actually not going to solve the problem
just to look up from your computer screen.
You need to go to a window,
you need to look out at a distance.
Ideally, you would even open the window
because those windows actually filter out
a lot of the blue light that you want during the daytime,
a lot of the sunlight.
It’s actually 50 times less gets through.
You want to get out onto a balcony.
You want to relax your eyes and look out at the horizon.
You want to go into what’s called panoramic vision
and let your vision expand.
You want this lens mechanism to be very elastic.
You don’t want it to get stuck in that configuration
of looking at things up close.
Accommodation is a wonderful feature of your visual system,
but you don’t want to push that too hard,
too often, or for too long.
You want to view the horizon.
You want to get outside,
not just to lighten the load on your mind
or to think about other things,
but to maintain the health of your visual system.
In other words, you want to exercise these muscles,
and that involves both the lens moving
and getting kind of thicker and relaxing that lens.
And the relaxation of the lens
is actually one of the best things you can do
for the musculature of the inner eye.
So what’s the protocol?
How often should you do this?
You might be surprised,
but for every 30 minutes of focused work,
you probably want to look up every once in a while
and just try and relax your face and eye muscles,
including your jaw muscles,
because all these things are closely linked
in the brainstem,
and allow your eyes to go into a so-called panoramic vision
where you’re just not really focusing on anything,
and then refocus on your work.
At least every 90 minutes of looking at things up close,
or even if you’re looking at a screen,
a television screen, or you’re watching a movie,
or you’re indoors,
for every 90 minutes of that,
you ideally would have at least 20,
probably more like 30 minutes of being outside,
ideally, but if you can’t be outside,
of non-up-close vision.
Now, you might say, that’s impossible.
How am I supposed to do that?
I’m in an office or I’m in a building.
Get to a window, get outside if you can do it safely,
get onto a balcony, and just let your eyes relax.
Many people are experiencing severe vision problems
because they’re not getting enough sunlight during the day.
They have sleep problems
because they’re not viewing sunlight early in the day.
And as I’ve mentioned in previous episodes,
they’re getting a lot of artificial stimulation,
artificial light stimulation of the eye
in the middle of the night.
All of this is through the visual system.
So migraines, fatigue,
challenges with your eyesight getting worse as you age,
or even in young people,
there’s at least according to the articles,
they describe it as this epidemic of myopia,
can largely be dealt with by getting outside,
going into panoramic vision,
experiencing some distanced vision,
look at things off on the horizon.
If you’re walking or hiking or biking,
not looking at your phone the whole time
that you’re doing that.
If you’re at the bus stop or you’re commuting,
certainly not looking at your phone
the entire time you’re doing that.
So this is vital.
And I want to emphasize another protocol,
although I don’t want to get into it in too much depth
because I want to make sure that I also talk about
a number of other important aspects of the visual system
that are more related to sight.
But getting into optic flow
is very important for de-stressing your system.
When you move through space,
whether or not it’s through walking, biking, even swimming,
if it’s self-generated optic flow,
so probably not driving or motorcycling,
but yes, bicycling or, I don’t know, unicycling.
I don’t know why I thought about unicycling.
There used to be a graduate student at Stanford
who was a really impressive unicycler.
Those are pretty rare.
As long as it’s self-generated optic flow,
meaning you’re generating motion of your body
and the visual images around you are passing by
on your eyes, that is very good for the visual system.
And it’s very good for the mood systems
and the neuromodulator systems of the brain and body
that regulate mood.
This is well-established.
So I’m not telling people to get away
from their phone and their computers.
I spend a lot of time staring at a page,
drawing, writing, texting, et cetera, just like you do.
But we’re really talking about some very simple protocols
that aren’t just designed to improve your sleep,
but are really designed to bolster and enhance your vision.
And of course, because it’s this podcast,
we will also talk about things that you can take
to improve your vision.
But if your visual behavior isn’t right,
and I do believe we should always start with behaviors
and then think about nutrition, supplementation, et cetera.
If your behaviors around vision aren’t right,
you cannot expect to have good healthy eyesight
for a long time, meaning throughout your lifespan.
And if your vision is already poor,
many of these things that I’m talking about today,
perhaps all of them will improve your vision to some degree.
And if your vision is starting to go,
then doing these behaviors is likely to really enhance
the quality of the vision that you will build
and maintain over time.
And all of these are essentially zero cost, okay?
If you live in a very dark environment,
like a cave or outer space,
it’s going to be hard to do some of this stuff.
But if you’re on planet earth, even if there’s cloud cover,
chances are you can do some or most,
or even all of these, some, most, or all days.
What I’m about to describe next is going to seem so silly
on the face of it, but has deep mechanism to support it.
Put simply, when you get tired, your eyelids close.
And when you’re alert, your eyelids are open.
That is because you have neurons in your brain
that depending on your level of alertness
will make it easy or hard to keep your eyes open.
Now that’s a complete duh,
except that we don’t often think about the relationship
between alertness and where we are looking and our eyelids.
Now, I learned this from a colleague of mine in psychiatry
who happens to work on hypnosis.
I’m not going to hypnotize you right now.
That’s actually for a future episode.
But what happens when we get tired?
Our eyelids close and our chin moves down.
We tend to nod out this way.
If you have ever been in a classroom,
certainly not one of mine,
but if you’ve been in a classroom
and the lecture is kind of drawing on,
or it’s the afternoon,
what you’ll notice is that a number of students,
their eyelids are closing and their chin is dropping,
and then you’ll see a bunch of heads bouncing back up.
I was definitely one of those people in class.
If it was post-lunch in the afternoon,
it’s warm, the hum of the air conditioner,
whatever it is, and I just out.
When we’re wide awake, the opposite happens.
Our eyelids are open all the way
and our chin happens to be up.
And no, this is not me telling you to have good posture.
However, what I learned from my colleague at Stanford
is that these circuits actually act in loops.
When we look up,
maybe it’s because these melanopsin cells
are in the bottom of our retina, they are,
and maybe it’s because they’re there
in order to view sunlight, which is overhead, which it is,
but that system of alertness
is linked to the position of our eyes.
So when we look up and our eyelids are up,
it actually has a purpose.
It actually creates a wakefulness signal for the brain.
And so while this might seem like the silliest
and simple tool that I might ever describe on this podcast,
if you are feeling tired,
it actually can be beneficial
to the wakefulness systems of the brain,
including the locus coeruleus
and these areas that release norepinephrine,
to actually look up, to actually look up toward the ceiling.
You don’t want your chin all the way back,
but to look up and to raise your eyes toward the ceiling
and to look up and try and hold that for 10 to 15 seconds.
So this isn’t looking up and closing your eyes
like on a nice sunny day, that’s relaxing.
This is looking up and actually looking up at the ceiling.
It actually triggers some of the areas of the brain
that are involved in wakefulness.
So if you’re somebody who’s falling asleep at your work,
this can be very beneficial.
Likewise, many people are looking at their phone all day
and their chin is down,
and then they’re sitting at a computer
that’s positioned below them
and they’re having trouble staying awake or focusing.
It can be very bad.
I tell Costello this all the time
because he’s always falling asleep
while he’s trying to do his work.
Positioning your computer screen up at eye level
or sometimes having it actually above eye level
can actually create wakefulness and alertness
for the work that you’re going to do.
This is simply because of this connection
between the brainstem circuits
and the other neural circuits that control wakefulness
and eyelids opening and looking up, okay?
So again, it’s remarkably simple, almost laughably simple,
but it’s grounded in some of the most hardwired,
meaning present from birth aspects of our neural circuitry.
And norepinephrine released from locus coeruleus
isn’t just a mouthful,
it’s a really interesting and powerful mechanism
for how the rest of the brain wakes up.
Locus coeruleus hoses the rest of your brain
with norepinephrine in order to wake up those circuits
for work and attention.
And so eyes up is actually a way,
a route into increased alertness.
Eyes down is a route into sleepiness,
into reduced alertness.
And I have only one friend that texts up here,
like on the street, holds his phone up here.
It looks ridiculous.
And yet, if we were trying to create
more sense of alertness, if that’s your goal,
positioning computer screens up high, chin up,
looking up if you need to kind of create
an alertness signal,
not always being chinned down and texting
or working into typewriters or reading below us
is actually going to send a recurring wakefulness signal.
When things are up, we tend to be alert.
When everything’s focused down, including our eyes,
it tends to have a more suppressive or sedative type
signaling to the deeper centers of the brain.
Now, before we move on to the science and tools
and protocols related to pattern vision,
I want to mention another study that was done
by the University of Pennsylvania.
They have a terrific group there that works on sleep.
They made an important discovery
that I think everybody should know about,
which is that children that sleep in rooms
that have a nightlight or dim lights
are much more likely to develop myopia, nearsightedness.
Conversely, children that sleep in very dark rooms,
so either very dim nightlights or complete black,
they have a much lower, statistically speaking,
a significantly lower probability
of developing myopia, nearsightedness.
Now, why is that?
It’s because the wavelengths of light that matter
for these melanopsin cells
oftentimes can get through the eyelids.
And that’s particularly true for children
and people that have thin eyelids.
Some people, like me, have very thin eyelids.
I’ve been told this before.
Not many people touch my eyelids,
but among those that have that very thin eyelids,
I notice I have very thin eyelids compared to, say, Costello.
Now, Costello’s eyes droop.
He can’t even close his eyes all the way.
They’re so droopy.
But many people have thin eyelids,
and those people are going to be even more prone
to light coming in through the eyelid.
So for parents, for kids, and for adults,
you really want to try to get to a place
where you can sleep in a completely
black or dark environment.
One little exposure to light, no big deal,
but this ties back to the other protocol
that I’ve described before in the mood and sleep episodes,
which is that viewing light,
even a very low intensity between the hours
of 10 p.m. and 4 a.m. is extremely detrimental
to the dopamine and other mood-producing systems
of the brain.
It can negatively impact learning and immunity
and even blood sugar and make people type 2 diabetes prone
by way of communication from these melanopsin cells
to a structure in the brain called the habenula.
Why am I throwing out all this verbiage?
Well, because people have asked for more mechanisms.
So if you really want to know, when you look at blue light,
or if blue light is getting in through your eyelids
in the middle of the night,
it is likely distorting these lens accommodation mechanism
in the eye and leading to myopia in some cases.
So that’s one reason to avoid blue light exposure
and bright light exposure,
even nightlight exposure in the middle of the night.
Viewing any light of bright intensity
between the hours of 10 p.m. and 4 a.m.
on a consistent basis is going to suppress dopamine
because of the way that that light activates
these melanopsin cells and the habenula
and the dopamine system.
So it’s all very simple.
Get as much bright light as you can safely, right?
You never want to look at any light so bright
that it’s painful to look at during the daytime.
Try and go without sunglasses unless you need them.
Now, I wear sunglasses for sake of sport
and sake of when it’s really bright out,
but I try to get two hours a day of working outside
or being outside, even if there’s cloud cover,
that’s going to offset myopia.
It’s going to help you get better sleep.
It’s going to support mood and metabolism, et cetera.
And at night, if you’re sleeping
with a lot of lights in the room,
and especially if there are kids that need a nightlight,
you should try and wean them off that nightlight
because it’s going to be beneficial for their vision
to wean them off that nightlight
and put them into a darker environment.
Obviously, you want to get them emotionally comfortable
with that first.
Now let’s talk about pattern vision,
actual seeing things like faces and colors, et cetera.
I’m presuming that some of you out there are colorblind.
We can all help the red-green colorblind folks out there.
By not using red in slides and diagrams
and on menus and things of that sort,
try and use magenta instead.
They can see the contrast between magenta and green better
than if there’s red and green.
So be kind to the colorblind folks out there.
It’s actually a fair percentage.
And there are a lot of different kinds of colorblind.
I should just mention some people are true monochromats.
They see the world in black and white.
That’s exceedingly rare.
Most colorblind people, colorblind in quotes,
are red-green colorblind,
meaning they lack red cone photopigment,
meaning they can’t see long wavelengths of light.
So they see the world much as a canine or a cat does
where they don’t get the green-red contrast.
That’s why we call it red-green colorblind.
They have the green cones,
but they can’t do the contrast comparison
that I described at the beginning of the episode.
So use magenta and they will be able to see things.
You wonder why stop signs and stoplights
and things aren’t in magenta.
Well, because the world is unkind
to the red-green colorblind individuals
and they have to learn the position
of those lights in the streetlights
and they have to learn the shapes of signs,
which they can do readily.
And it usually says stop on it as well.
But if you care about colorblind folks, which I do,
then we could all do them a service by,
I think by law actually in the US,
menus are required to be colorblind accessible.
How can you improve your vision?
How can you get better at seeing things?
Well, one way is to make sure that you spend
at least 10 minutes a day total, at least,
viewing things off in the distance.
So that would be well over half a mile or more.
Try and see a horizon,
try and get your vision out to a location
that’s beyond the four walls of your house or apartment
or the doors of your car and the windshield of your car.
I know that can be hard to do, but it’s very valuable.
If you live in a city like New York
and it’s skyscrapers everywhere,
you’ve probably experienced the incredible
sense of relaxation.
And it’s aesthetically beautiful
when you are walking down one of these long avenues
and you turn.
And I think they have a name for this in New York
where the sunset is suddenly visible
along a long avenue between some skyscrapers.
And it’s just very relaxing to be able suddenly
to see at a distance.
And that’s actually because this eye mechanism
relaxing the lens and relaxing some of the musculature
around the eyes,
send signals deep into the brainstem
that release some of the centers
that are involved in alertness, AKA stress.
And it’s very pleasant for a reason.
It’s not a placebo effect, if you will.
There are a bunch of neurochemicals
and things that are associated with that.
So try and see at a distance
because it’s good for your eyesight.
It’ll keep this lens nice and elastic
and the muscles nice and strong that move the lens.
And it has this relaxing component to it.
Our visual system is exquisitely tuned to motion,
not just our self-generated motion,
but the motion of things around us.
And one of the things that it does
is something called smooth pursuit.
Smooth pursuit is our ability to track individual objects
moving as the name suggests,
smoothly through space in various trajectories.
You can actually train or improve your vision
by looking at smooth pursuit stimuli.
And that sounds really boring.
What you can do is, and I’ll provide a link to some
that I think are pretty good
that are used in various clinics,
ophthalmology and optometry clinics.
You can actually take a few minutes each day,
or maybe if you don’t do it each day,
you could do every third day or so,
and actually just visually track a ball.
Sometimes it’s moving in and kind of an infinity symbol.
Sometimes it’s more of a sawtooth.
Sometimes it’s changing speed.
Sometimes the cue that you’re following,
the little target is dilating and contracting.
This is going to keep the muscles, I want to be clear,
this is going to keep the extraocular muscles
conditioned and strong,
and allow you to have a healthy smooth pursuit system.
Remember, the brain follows the eye.
It follows the movements of the eye.
It has to deal with that.
And the neural circuits within the brain
have to cope with changes in smooth pursuit.
So if you’re doing a lot of reading up close,
you’re not viewing horizons,
you’re not getting a lot of smooth pursuit type stimulation
from your life,
or you’re just getting it within the confines
of a little box on your phone,
like your smooth pursuit is over millimeters
or what we always talk in terms of visual angle,
but the amount of degrees of visual angle.
But if you’re just looking at smooth pursuit
in this little tiny box on your phone
or on your computer screen,
and you’re not looking at objects in your environment,
like swooping birds and things like that,
which I’m guessing many of you
are not spending your time doing,
well, these mechanisms for smooth pursuit
will get worse over time.
Your vision will get worse.
And so while I prefer that people get out
into the real world and experience
smooth pursuit tracking of visual objects,
I don’t know, maybe it’s a good reason
to go to a hockey game or, you know,
and try and keep your eye on the puck,
which I can never seem to do, move so fast.
Or I guess this is a good reason to watch live sports,
if that’s your thing,
or watch a tennis match like a cat, like a kitten,
watching the ball go back and forth.
Whatever, watching kids play, it doesn’t really matter.
The idea is that you want to use the visual system regularly
for what it was designed for,
and smooth pursuit is a great way
to keep the visual and motion tracking systems
of the brain and the eye and the extraocular muscles
working in a really nice coordinate fashion.
I would say five to 10 minutes, three times a week,
will be great.
If you care about your vision,
you can train your vision in this way.
The other one is to train accommodation.
There are a lot of videos out there,
I want to be clear, on the internet,
some of which are from clinicians, some of which are not,
some of which are from scientists,
some of which are from other sources,
talking about things you can do to make your vision better,
to improve your vision.
Most of those are geared toward
improving the extraocular eye muscles.
But I did consult with our chair of ophthalmology
at Stanford School of Medicine, Jeff Goldberg,
who’s an MD and a PhD, a phenomenal scientist
and a phenomenal clinician,
and incidentally, a phenomenal chairman as well,
about what sorts of things, tools,
are actually beneficial for pattern vision and sight,
because there’s just so much out there on the internet,
not all of which is accurate or good, frankly.
And he agreed that a smooth pursuit stimulus,
that kind of training, as well as, or exercise,
as well as near-far.
So spending a few minutes,
you might even just do this for two minutes,
of looking at something up close,
that’s going to activate these accommodation mechanisms,
and then moving it at arm’s length
and focusing on it for five, 10 seconds, maybe more,
maybe 15 or 20 seconds,
then slowly moving it into a location and then out.
This is actually a lot like the visual training
that’s done post-concussion to try and repair,
actually repair some of the balance and motor and visual
and cognitive aspects of the brain.
And we are going to have a guest on in a future time,
that to deal with concussion
and some post-concussion training,
a lot of post-concussion recovery and training
centers around the visual system,
not just because people are trying to recover their vision
and their sense of balance,
but because, as I mentioned earlier,
the brain’s ability to make sense of its environment
and the brain’s ability to parse time,
not just on the day-night schedule,
but also shorter time intervals,
follows the visual system.
Something we’ll turn to a little bit more at the end.
So what does this mean?
The tool is spend two to three minutes
doing smooth pursuit.
There’s some programs on YouTube.
You can just look up smooth pursuit stimulus
and I’ll provide a link to a couple I like as well.
You could do this with a pen if you wanted.
You could do this,
someone else could hold a wand and you could do that.
If you’ve got someone that can do that for you,
practice accommodation for a few minutes,
maybe every other day, just bringing something in close.
You’ll feel the strain of your eyes doing that.
I can feel it right now.
Move it out.
You’ll feel a relaxation point.
Move it past that relaxation point
where you will have to do what’s called a virgin’s eye
movement to maintain focus on that location
as it moves out, bring it back in.
At the point where you actually have to go cross-eyed,
this will differ for different people
depending on how far apart your eyes are,
so-called interpupillary distance.
So for me, I have been teased before
I have a very short interpupillary distance.
I’m not a cyclops, but I’m heading there.
Some people are more wall-eyed, like a flounder.
Well, depending on your interpupillary distance,
the point at which things get blurry
and cross-eyed will vary.
But for me, you know, as I get about,
oh gosh, I guess it’s about six inches from my nose,
it’s really hard, I can’t accommodate any longer.
I move it out another inch and everything’s in nice focus.
Try and see whether or not you can get things closer.
Now, you don’t want to get cross-eyed.
Remember what your parents told you?
Or my parents told me that if you cross your eyes
when you’re young, that they can stay that way.
Actually, they won’t necessarily stay that way,
but your brain can start losing information
and the ability to see binocular depth,
something we’ll talk about in a moment.
But for now, the protocol would be, you know,
two to three, maybe five minutes.
Just practice that, practice accommodation,
and then be sure to give your eyes some rest.
Get outside, look at a horizon, or do nothing.
Just kind of let your eyes go soft.
I guess what the yogis would call soft gaze.
Just kind of relax your eyelids.
Not this, not eyes closed.
Just relax, panoramic vision.
Try and see the walls around you without moving your head.
Exercise your eye muscles.
Exercise the accommodation mechanisms of your eyes.
Practice a little bit of smooth pursuit.
You don’t have to be neurotic about this,
but if you do this often enough,
meaning every other day, every third day or so,
you can be the strange person on the plane
or in the classroom doing this.
You know, people might chuckle or look at you funny
or tease you, but that’s okay
because you’ll be able to see
when they are losing their vision.
So you’ll get the last laugh.
Please don’t laugh at them,
but maybe you can help them at that point.
You can hold the pen for them.
It’s worth doing.
It’s really worth preserving your vision.
And again, if you’re a young person, this is great
because then you can actually build
an extra strong visual system
using all the tools that we’re describing.
I do want to talk about a new set of findings
that are related to red light
and offsetting age-related macular degeneration.
There are a lot of ways in which our visual system
gets worse over time,
but one is so-called age-related macular degeneration.
Glenn Jeffrey at the University College of London,
somebody I’ve known for decades because he’s a scientist,
has done beautiful work on development
and function of the visual system,
has published a number of papers recently.
One that got a particularly high amount of attention
in the press was one that showed
that flashing red light into the eyes early in the day,
not late in the day, early in the day,
can help offset some age-related macular degeneration,
presumably by enhancing the mitochondrial function
in the photoreceptors.
There does seem to be some evidence for that,
although it’s still early days.
I want to emphasize,
you don’t want to shine really bright lights into your eyes.
You never want to look at any light that’s so bright
that it’s painful.
And you never want to force your eyelids to stay open.
If you need to close your eyes in order to be comfortable,
well, then chances are that light is too bright.
But doing just a couple minutes a day,
two minutes a day of flashing this red light
into one eye and then the other,
as long as it was early in the day, before noontime,
and as long as it was in individuals
that were 40 years or older,
did seem to have a significant effect
in offsetting some of the age-related macular degeneration
that would otherwise occur.
Again, these are early findings.
If you want to do this, please be careful.
Please talk to your optometrist and or ophthalmologist.
Your eyesight is precious.
You don’t want to damage it,
but it is interesting,
and it does seem like red light
can improve the function of the mitochondria.
These photoreceptors have a lot of mitochondria,
the energy-producing organelles within the cells,
because they are some of the most metabolically active cells
in your entire body.
Your photoreceptors are active all the time
as you’re looking around,
and even when your eyes are closed, they’re active.
In fact, through a weird twist of the biology,
and please look this up
if you’re really interested in this,
your photoreceptors are actually most active in the dark.
This is so weird.
It’s a twist of biology, the way the system’s arranged,
that when light comes on, they shut off their activity.
So actually, whether or not you see something
in front of you like this pen or my face
is because the way your photoreceptors are turning off,
not turning on.
It’s a really cool twist,
and I don’t want to go too far down that rabbit hole,
but check it out.
If you’re interested in how photoreceptors work,
it’s an absolutely incredible literature.
Just Google, excuse me, look up on the web.
We are not partial just to Google.
I happen to use Google,
but use your web browser to look up
photoreceptors hyperpolarization site,
and you can learn a lot about that
if you’re a real nerd for this stuff like I am.
Okay, so red light to the eye can perhaps, it seems,
help maintain vision, doing smooth pursuit exercises,
and accommodation, near-far exercises.
Some people suffer from poor eyesight
simply because their eyes get dry.
There are incredible, believe it or not,
lubricating mechanisms for the eye,
not just tears, but thin sheet of oil.
I mean, it’s just amazing.
Unless you have some sort of corneal abrasion,
the cornea is the clear stuff on the outside of your eye,
corneal abrasion, when you blink, it’s smooth.
You don’t feel it.
It’s just really, really smooth,
and yet if you’ve ever had a corneal scratch,
I’ve had this, it’s really rough.
It is so painful.
You have a ton of pain receptors in the cornea.
The lubrication of the cornea is supported by blinking.
And while it seems a little silly,
some people actually benefit from doing, you know,
some, you know, five or 10 or 15 seconds of blinking,
and then doing their focused work.
Some people, their eyes are drying out
because as we focus, if we’re trying to do something,
our eyelids stay open, the eyes can dry out,
but it also can make it such that
when we blink the next time,
there’s a kind of a need to focus
because there’s some distortions in these oils and liquids
across the corneal surface.
If you’re somebody who suffers from dry eye,
I do hope they’ll find a treatment or a cure for dry eye
soon, there isn’t one at present.
Someone stands to make a lot of money out there.
If you can find a cure for dry eye,
let the companies know or start a company.
Right now, it’s still a mystery as to how to do that,
but blinking for five to 15 seconds,
probably slowly, not as quickly as I’m doing here on video,
but just, you know, maybe a blink every second or two,
for 15 seconds can lubricate the eyes.
And that’s not directly related to anything neural,
it’s just going to allow the optics of your eye to be clear.
Just like when the screen of your phone gets dirty,
like when Costello is texting on my phone
and I pick it up and it’s like covered with smudge,
to clean it off in order to see things clearly,
the same thing is happening for these optical devices
on the front of your brain.
Remember, these are brain.
Okay, so a lot of protocols today, almost all of them,
I do want to talk a little bit more about vision
and how it works internally.
And then I also want to talk about
some of the foods and supplements that have been shown
to support vision and offset visual loss,
and maybe even reverse some visual loss.
Let’s talk about binocular vision and lazy eye.
I’m very familiar with lazy eye because when I was a kid,
I went swimming one day, one day,
and I didn’t have my goggles.
And so something must’ve been happening, as I recall,
with the eye moving down through the water.
I’ve always had this problem that I can only do
the freestyle stroke off to one side.
The people I swim with are always laughing.
Somehow I kind of move toward drowning
when I try and breathe on the right side.
I think there’s some asymmetry in the way I’m organized.
Anyway, I was off to my left and my eye kept going
in and out of the water and there was chlorine in the water
and it was making my eye uncomfortable,
so I just closed my eye.
I just decided, you know,
I knew more or less how to swim straight-ish.
Might’ve bounced off the lane lines a few times,
but I just used the other eye to kind of steer
for that mark on the wall.
Got out of the pool, took a shower, dried off,
and then completely lost binocular vision for three days.
The young brain, up until about age seven,
but maybe even extending out until about age 12,
is extremely vulnerable to differences in ocular input
between the two eyes.
My scientific great-grandparents won the Nobel Prize
for discovering so-called critical periods,
periods of time in which the brain is more plastic,
more able to change.
Those two guys, David Hubel and Torsten Wiesel,
thank you, David and Torsten,
forever changed the face of visual neuroscience
and forever changed the way we think
about treatment of the young brain.
It used to be thought that you wouldn’t want to do a surgery
on a young kid because of risk of anesthesia
in young individuals,
but we now know that you need to repair these imbalances
that even a few hours, okay?
I don’t want to scare anybody.
I’ll talk about reversal,
but a few hours of occluding one eye early in life
can lead to permanent, unless something’s done,
permanent changes in the way that the brain perceives
the outside world,
such that when that eye is opened up again,
the brain actually can’t make sense of anything
that’s coming through it.
It shuts down that visual pathway somehow.
So what happened to me was I actually was,
my eye was fine.
I got out of the pool, I opened my eye,
but I couldn’t see through that eye.
Everything was blurry, double vision,
unless I covered this eye,
and then I could see perfectly fine.
Fortunately, I went to an ophthalmologist
who understood the literature.
Thank you, Dr. Mark Lurie,
who understood the literature
and made it clear that what I needed to do
was to occlude the other eye,
the eye that was working very well.
Clearly he understood the work of Hubel and Wiesel.
Now, again, you don’t want to start playing games
with this kind of stuff when you’re a kid.
If you wear, let’s say you have a Halloween costume
and you wear an eye patch,
you’re a pirate or something for Halloween,
and you cover it up on one side,
probably for the night of Halloween, it’s okay.
I do not recommend doing that recreationally
if you don’t need that,
if you’re a young child or for your child to do that,
because indeed you create imbalances in the brain machinery
that compares information coming in through the two eyes,
and it can shut down the neural information
for the occluded, the closed eye.
Now, I was able to reverse this issue,
but my binocular vision has never been terrific.
I’m much better at the dartboard and still not very good.
If I close one eye, I’m much better at the pool table.
If I close one eye and I still am terrible.
I was the kid and, you know, in the outfield,
you know, the ball’s coming towards me,
the ball’s coming towards me.
I’m going to catch the ball
and like a hit me square in the lip.
My binocular vision isn’t great
as a consequence of this early event.
And I have a hard time with those binocular stereograms,
those images that are kind of,
you’re supposed to look at them,
and then the binocular depth image like pops out.
All the other kids were going,
there’s the whatever, the Statue of Liberty,
there’s the American, I see dots, okay?
So I have binocular vision, but I use other cues.
I use the near-far cues that I talked about before,
motion parallax, the fact that things are closer to me
are moving faster than things further away
in order to judge depth.
And years later, when I got involved in,
and I don’t suggest this for most people,
I got involved in boxing and martial arts when I was younger.
Sometimes we’ll see fighters,
this is a slip to avoid getting punched.
It’s also generating motion parallax.
Many animals judge depth by moving their head,
not by using other mechanisms of accommodation, okay?
So a lot of birds and monkeys and animals
will judge depth by moving their head like this,
or they’ll move from side to side.
Animals that will undulate sometimes
are actually doing a depth measurement
because as you move from side to side,
the brain is able to do the math of depth.
So what does this all mean in terms of protocols?
If you’re a young person,
do your best to get really good binocular vision,
not just at level of your phone or your tablet,
but also at distance.
You will build strong binocular visual machinery
in the brain and at the level of the eyes
and the eye musculature.
Now, if you’re somebody who did have an occlusion,
what’s needed is to cover up the other eye,
to create an imbalance so that the weak eye,
the so-called lazy eye,
that’s sometimes referred to as amblyopia,
that eye has to work harder.
So for me, they patched this other eye and made this eye,
eventually I got vision through that eye back,
then they opened them both up.
Now, you might ask,
what happens if you cover both eyes early in life?
And this is where it gets interesting.
You might think, well,
if covering one eye leads to poor vision for that eye
after that eye is open,
covering both eyes will probably make you blind, right?
Actually, that’s not what happens.
What Hubel and Wiesel discovered
and what’s been affirmed many, many more times over
in subsequent studies is that it’s competitive,
that the two eyes are competing
for real estate up in the brain.
So if you actually cover both eyes,
you actually extend the period of critical plasticity.
This is a really interesting aspect
that other people are starting to leverage now
in terms of how to reopen plasticity later in life.
But please don’t go around
with your eyes covered for too long.
There are some like retreats and stuff
where people go into caves with absolutely no vision,
We’ll talk about why that is in just a moment.
But here’s my suggestion.
Try and get balanced visual input through the two eyes.
Almost everybody has a dominant eye.
It usually doesn’t relate to your dominant hand,
although it can.
And so for me, if I cover up my right eye,
I see much less well, much more poorly.
It’s a little bit fuzzy and I have to work harder
in order to see the camera, for instance.
Then if I cover up my left eye,
it’s actually really easy for me to relax.
I have a dominant eye.
Yeah, you can balance that out
by covering up the dominant eye a little bit each day.
But I would warn any young people,
meaning 12 or younger, against creating these imbalances
if there isn’t a clinical need to do that.
And if you do have strong imbalances between the two eyes,
which can be caused by cataract and lens issues,
can be caused by neuromuscular issues, et cetera,
to try and get those dealt with as early as possible
by contacting a really good ophthalmologist
and ideally a neuro-ophthalmologist.
It is very normal, I should say it’s very common
for young children, babies to have an eye with strabismus
that either deviates out or that deviates in.
It is important to correct that
if you would like to have balanced vision
between the two eyes and for the brain to respond
equally to the two eyes and to have,
I would say high fidelity quality vision.
Although some people who have an eye that drifts
can function normally in life,
you have an opportunity early in life to rescue that.
I won’t do, well, maybe I will do this,
but I can actually relax this eye.
It’s so weak in some cases
that it actually can start to deviate.
Here, I’ll just do this here.
It’s not crossing my eyes.
So I actually can move my, I can misalign my eyes
because I have to fight very hard
to have the musculature for this eye
keep that eye aligned with the other eye.
And that’s because I’ve been doing eye exercises
since I was in my 20s
because I noticed when I would study a lot,
this eye would start to drift in.
I’d start to see double
and then next thing you know,
I was just covering the eye up.
It was getting weaker and weaker,
just like the atrophy of a muscle.
So I went to the doctor.
What did they do?
They did the exact wrong thing.
The optometrist I went to gave me a prism
which adjusted it so that I could see things normally,
which just made the eye weaker and weaker.
It’s like putting a weak arm into a sling.
So I had to spend at least three years of 10 minutes a day,
it’s what I recommend,
doing near-far, covering up my good eye,
doing near-far with my bad eye,
and now it’s been about 10, 12 years
that I have pretty decent binocular vision.
Now, many of you aren’t dealing with this
or have these early childhood issues.
Some of you might be experiencing challenges
with fatigued eyes
or with differences in focus with the two eyes.
These eye exercises of near-far, smooth pursuit
and checking for dominant and non-dominant eye
can be very beneficial.
Again, I’m not a clinician,
so I don’t want to give you protocols
or enforce protocols on anybody.
You need to figure out what’s right and safe for you,
given your vision history.
I do recommend talking to a really good ophthalmologist
if you have severe vision problems of any kind,
or if you want to offset vision problems of any kind,
an optometrist as well,
but ideally it would be a neuro-ophthalmologist.
Okay, I did mention hallucinations
and they’re fun to talk about and think about.
For years, people have asked,
why do people get visual hallucinations?
Costello’s in sleep right now.
You can probably hear him snoring.
He’s snoring so loud.
He’s probably having hallucinations about rabbits, pizza,
and those are mainly his favorite thing, and sleep.
He’s dreaming about sleep in sleep.
Hallucinations are a property of the visual system,
and it was always thought that hallucinations arise
because of over-activation or activation
of certain aspects of the visual system.
I just briefly want to mention a paper
that was published by my good friend
and phenomenal scientist and physicist for that matter,
Chris Neal, who’s up at the University of Oregon in Eugene.
They studied LSD-like compounds and discovered
that hallucinations actually occur
because portions of your brain become underactive.
The visual portions of the brain are under-stimulated.
This is probably why when people go into these cave retreats,
something I’ve never done, I don’t think I ever will do,
where it’s completely black,
pretty soon they start hallucinating.
They start seeing things even though there’s nothing there.
The visual system is desperate to make guesses
about what’s out in the world.
It’s like the eager beaver of your brain.
It’s like, what’s out there?
What’s out there?
What’s out there?
Even in low to no vision people, blind people,
their brain is going to be making guesses
about what’s out there in the auditory world,
what sounds are there, what touch sensations are there.
For sighted folks, it’s going to be
what’s out there in terms of light.
Light is the dominant way,
vision is the dominant way
that we evaluate the world around us.
So it turns out that hallucinations
are an under activation of the visual system
and then a compensatory, a compensation
by which the visual system creates activity
So if you’re in the dark long enough,
you start to hallucinate and see things.
So that’s a little note about hallucinations.
One of the things that you can do to improve your vision,
and it’s also kind of fun,
is to put a Snellen chart in your home.
A Snellen chart is that list of letters.
If you go to the dreaded Department of Motor Vehicles,
actually I’m up for renewal soon.
So I love the Department of Motor Vehicles.
The Department of Motor Vehicles
will have you cover up an eye,
read the letters on the chart.
The letters of course get smaller and smaller.
They’re trying to figure out roughly what your vision is.
Cover up the other eye, you’ll do that.
Some people, including nerdy vision scientists like me,
have had Snellen charts in their office
or in their home for many years now.
And you can just practice and you can see how you’re doing
sitting at a particular distance.
This is something that’s not often mentioned,
but your performance on the Snellen chart will vary
depending on time of day,
because your level of fatigue
and your ability to control that accommodation
and other mechanisms of the eye muscles will vary.
So you can take it as an average.
It’s also a good thing
if you’re going to get your vision tested
for corrective lenses,
or maybe you’re going to do laser surgery
or something of that sort.
If you’re thinking about any of that,
to really get it measured by a professional,
the ones that you get in those supermarkets
or in many eyeglass stores,
apologies to the eyeglass stores,
are often wrong by an order of magnitude.
And then when you start putting corrective lenses on
that are over-correcting or under-correcting,
but more often are over-correcting,
then you’re essentially weakening the system.
It’s like putting a prosthetic on a limb
that you didn’t necessarily need,
or a robot arm when you didn’t need
the use of the robot arm.
Although now there’s so much excitement about robots.
I think people are going to be doing that.
get your vision tested by somebody
who really understands vision,
like an ophthalmologist or a really good optometrist.
If you put a Snellen chart in your home,
you can do that as part of your visual training.
Now, this might seem excessively nerdy,
but what is more important than your eyesight?
Eyesight is so vital.
It’s right up there with movement
and our ability to move, to generate,
to get up out of chairs and to walk and to run
and to take care of ourselves.
Eyesight and movement are the main ways
that we are able to take care of ourselves
and take care of others.
When you start having compromised eyesight
or compromised movement,
people need to take care of us
and we become much more challenged
in moving through our daily life.
So while it might seem nerdy
to have a Snellen chart in your home,
or to do a smooth pursuit exercise a couple of times a week,
or to get outside for a few hours a day
and do your reading or your laptop work there,
preserving your eyesight and preserving your vision
is one of the most life enhancing
or quality of life enhancing things that you can do.
And if you’re a young person
and you can build some of this
into your framework of exercise or brain training,
if you want to call it that,
that can be immensely beneficial
and will really set you up to have really good vision
over a long period of time.
Now, of course, there are genetic factors
and there are injury related factors
that can compromise eyesight and our ability to see.
And of course, the things I’m talking about today
aren’t going to solve all those issues,
but they can have a tremendous positive impact
if you’re willing to do just a little bit of work.
And none of this is involving any cost, right?
It’s just time cost.
So I do want to talk about a few other things
that can perhaps improve vision.
I want to dispel a few myths
about stuff to take to improve vision.
And then I want to just close
by talking about how we perceive time using our vision,
because that will nicely set the stage
for what we’re going to talk about next episode.
So now you understand a lot about the biology of vision.
You understand that light has to arrive at the retina
and get converted into electrical signals.
That process requires things like vitamin A,
a fat soluble vitamin.
It requires things like the carotenoids.
That metabolic cascade,
that biochemical cascade is essential for vision.
And this is why you’ve been told
that carrots help you see better
because they’re high in vitamin A.
There are a few simple things you can do
to support your vision.
First of all, it is true that eating vegetables,
the dark leafy vegetables,
and things like carrots that have vitamin A in abundance,
and eating them in close to their raw form,
so naturally occurring foods
that contain a lot of vitamin A in their raw form
can help support vision.
Now, does that mean that if you ingest
super physiological amounts of that stuff
that it’s going to make your vision that much better?
No, but you do need a threshold level of vitamin A
in order to see, and in order to see well.
Now, there’s a lot of excitement nowadays
about supplementation to help support the health
of the visual system.
And I’m somebody who’s pretty open
to novel forms of supplementation.
You’ve probably gathered that
if you’ve been listening to this podcast for a while.
You have to determine what’s safe,
and economical, and right for you,
what your risk tolerance is, et cetera.
But I want to talk about a molecule
that’s in a lot of supplements to support vision.
And there are some really good data on, and that’s lutein.
Now, the study I want to describe
is actually published in 2016.
It’s from the Journal of Ophthalmology.
It’s a good journal.
And the title of this paper might catch your attention.
It’s Increased Macular Pigment Optical Density.
That just means that the macula is an area of the eye
for central vision, for high acuity vision.
Pigment density there is good.
You want pigment there.
Increased macular pigment optical density
and visual acuity.
Visual acuity is your ability to see things in fine detail.
Following consumption of a buttermilk drink
containing lutein-enriched egg yolks.
Remember raw foods?
Lutein-enriched egg yolks.
Sounds like a Rocky movie
where he would drink the raw egg yolks.
A randomized double-blind placebo-controlled trial.
Now, I’m not suggesting you go out and eat raw egg yolks.
There’s the risk of salmonella.
Although I did hear this, someone correct me if I’m wrong,
that the salmonella is actually on the outside of the egg,
not actually in the egg itself.
It’s on the shell for reasons that relate
to how that egg got into the world.
That’s where the salmonella lives.
But I could be wrong about that.
But raw egg yolks are not something
that most people want to consume.
What is this lutein stuff?
Well, lutein is in the pathway that relates to vitamin A
and the formation of the opsin, the photopigment
that captures light in the back of your eye,
literally absorbs light pigment in your eye
and converts that into electrical signals
and allows you to see.
And there is some evidence.
I spoke to our chair of ophthalmology.
There is some evidence through quality peer-reviewed studies
that supplementing with lutein can help offset
some of the detrimental effects
of age-related macular degeneration.
But, I want to emphasize but, or emphasize however,
only for individuals with moderate
to severe macular degeneration.
For people that have normal vision
or with just a low degree of macular degeneration,
these studies did not see a significant improvement
of vision from supplementing with lutein.
So, I’m not going to tell you
to supplement with lutein or not.
I don’t think any study is holy,
but it does seem that if you have moderate
to severe macular degeneration,
talk to your physician of course,
talk to your ophthalmologist.
I’ll always say that and I’ll say it three times.
Supplementing with lutein could perhaps
support vision and offset some visual loss in that case.
Probably also talk to your ophthalmologist
or consider the red light therapy
that I talked about earlier.
Whereas if you have normal vision
or a low amount of macular degeneration,
it does not seem at least from these studies
that lutein can have much of an effect.
Now, I know and I confess I’m sort of of the mind
that if I personally had age-related macular degeneration
or a propensity for it in my family,
which fortunately I don’t.
But in that case, I would think that supplementing
with lutein provided it’s safe,
could perhaps be of benefit.
You might want to consider a low dose of that.
So again, I’m not pushing any of this on anybody
by any means, but you should know that
under certain conditions of severe macular degeneration
or moderate macular degeneration,
it does seem like lutein can be beneficial.
It does not have to be consumed through raw egg yolks,
although that is the highest density source.
Cooking your eggs, if you like your scrambled eggs dry
or you like your eggs not easy over or whatever, not runny,
then you aren’t going to get the benefits of the lutein.
There are other sources of lutein,
non-animal sources of lutein as well.
You can look those up on the internet.
Now, there are other compounds that have been shown
to perhaps be important for offsetting
or helping different forms of vision loss.
One is, I’m going to spell this out,
I-D-E-B-E-N-O-N-E, indabone, indabenone, indabenone.
I can never pronounce these compounds, forgive me,
unless I’ve worked with them.
There is evidence that it can be beneficial
for Leber’s congenital eye disease.
I would definitely go onto examine.com, put in I-D-E-B-E-N-O-N-E
and for things like Leber’s optic neuropathies,
which is a degenerative condition of the eye.
Whether or not people should just be taking this stuff
anyway is still an open question.
There aren’t a lot of studies about it.
A lot of people that are interested in taking things
to support their vision are taking lutein
as a preventative measure.
I don’t pass any judgment one way or the other.
Typically those supplements also include the zeaxanthins
and the astaxanthins.
Okay, the pronunciation of this is terrible, I’m sure,
but that’s not too far off,
but basically Z-E-A-X-A-N-T-H-I-N.
You can see why it’s hard to pronounce, Z-E-A-X-A-N-T-H-I-N.
And the other one is A-S-T-A-X-A-N-T-H-I-N.
Both of these have been shown, excuse me,
both of these have been shown to offset some
of the disruption in vision that occurs with aging.
What is Aztec saxanthin?
It’s a really interesting compound.
It’s the red-pink pigment found in various seafoods.
So shrimp, I’m not a big seafood fan,
but like certain fish, like the,
you’ll see at the fish market
will have that red-pink pigment.
And it’s also in the feathers of flamingos.
Please don’t eat the feathers of flamingos
and please also don’t eat flamingos.
It’s structurally similar to beta carotene.
So it’s very pro-vitamin A,
but it has some chemical differences
which may make it safer than vitamin A.
Remember vitamin A is a lipid soluble vitamin.
So it can be stored in our body for long periods of time.
What is the deal with this Aztec saxanthin?
You know, what are its drawbacks?
Well, we can go to our ever favorite examine.com.
What does it do?
Well, it has a number of different effects,
a huge number in fact,
but it does seem to notably increase,
it’s now been shown in three studies,
the antioxidant enzyme profile.
It has a number of different effects,
but the most notable for sake of this episode
is the one on ocular blood flow.
It does seem to increase the amount of ocular blood flow.
So the blood supply to the eyes.
So that makes it an interesting compound.
It has a number of other effects for whatever reason.
It also has a notable effect,
several studies have shown this,
on fertility in males.
So it seems to at least double the pregnancy rate
when men take Aztec saxanthin
and works as in particular, it seems here,
in men that were previously infertile.
So I don’t know if that has something to do
with the blood flow to the eyes, probably not.
It probably has something to do
with something unrelated to the eyes.
Nonetheless, that’s an effect of this molecule.
It’s also been shown to have positive effects
on things like skin elasticity, skin moisture,
skin quality, et cetera,
probably due to its effects on blood flow.
So lutein, azaxanthin, A-S-T-A-X-A-N-T-H-I-N.
And for people who have concerns
about Leber’s optic neuropathies,
which is going to be a small percentage
of people out there, but that is a pretty severe condition.
There are supplements that are available out there.
I do encourage you as always to talk to your ophthalmologist
and physician about them.
And I will say that there are a number of people
that take lutein and some of these other things
as a precautionary measure
in order to bolster their health.
In the same way that some people take vitamins and minerals
to bolster their health, and some people are very health,
excuse me, and some people are very averse
to taking vitamins and minerals
because they feel like they can get all that
from healthy whole foods.
And of course you can get these things from whole foods.
The question is whether or not you can get them
in concentrations that are sufficient.
I do think that in the years to come,
we are going to see more about lutein.
I think we are going to see more
about some of these other compounds like astaxanthin,
and hopefully by then I’ll be able to pronounce it.
But at present, these things are more or less
in the kind of experimental or self-experimental phase.
There are some good double-blind placebo-controlled studies
like the egg yolk buttermilk study of all things
published in really good journals.
Journal of Ophthalmology,
Journal Investigative Ophthalmology and Vision Sciences.
These are good journals.
These are journals that are peer-reviewed by experts.
The study that I mentioned earlier
about keeping rooms dark,
that was also published in an excellent journal.
I think it was JAMA.
I’ll go back and look.
It’s not on my screen any longer, but very easy to find.
And there’ve been some follow-up studies as well
from the University of Pennsylvania and other universities.
So everything I’ve talked about today
relates to studies that were done
and published in quality peer-reviewed journals.
That doesn’t necessarily mean you want to run out
and start taking the stuff that I’ve described
or even doing the protocols I’ve described.
I’ve given you an array, a palette, a buffet, if you will,
of things that you could do to try and enhance
or support your vision,
depending on how good your vision is,
your family history of vision and vision loss,
your occupational hazards.
You know, people that work with metal filings
that are flying out of machines
are going to have a higher degree of vision,
you know, risk to their visual system
than will people who just do office work.
Although if you’re doing a lot of office work,
chances are you’re not getting a lot of long view vision,
your accommodation mechanisms
are going to start to suffer over time.
I think we can reliably predict that.
So I’ve tried to give you an array of behavioral tools
and we did touch upon some supplementation tools.
I’d be remiss if I didn’t say that
because blood flow is so critical
for the neurons of the eye,
remember these are the most metabolically active cells
in your entire body, the cells within your retina,
because blood flow is required
to get them the energy and nutrients they need.
Having a healthy cardiovascular system, right?
Doing endurance work, doing strength training work
regularly is going to support your eyes
and your brain and your vision.
It’s indirect, but it’s essential, right?
It’s necessary, but it’s not going to be sufficient.
You’re going to have to do other things
to support your eyesight as well.
But having a healthy cardiovascular system
because it’s going to deliver blood and oxygen
and nutrients to this incredible apparati
on the front of your face,
these two pieces of brain is going to support
your overall brain health and vision over time.
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And last but not least,
I want to thank you for your time and attention today.
Your willingness to learn about vision
in the visual system and the various things
that you can do to help support the health
and functioning of your visual system.
And of course, I want to thank you
for your interest in science.
And I’ll see you next time.