Huberman eyes transcript

ANDREW HUBERMAN: Welcome to the Huberman Lab podcast where we discuss science and science-based tools for everyday life.
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[MUSIC PLAYING] I'm Andrew Huberman, and I'm a professor
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of neurobiology and ophthalmology at Stanford School of Medicine. Today is an Ask Me Anything episode, or AMA.
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hear the first 20 minutes of today's episode and determine whether or not becoming a premium subscriber is for you.
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And now without further ado, I will answer your questions. And as always, I will strive to be
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as thorough as possible, as clear as possible, and as concise as possible.
What Are the Best Eye Exercises, Supplements, Food, Protection Practices for the Eye?
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The first question is about eye health, in particular eye health protocols
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for people that are aging but eye health protocols for people in general. The question is, I'm noticing that my vision,
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both close and far, is deteriorating. What are the best eye exercises, eye health behaviors,
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supplements, et cetera for the aging eye? So the answer I'm about to provide applies to everybody regardless of age,
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which is, you want to make sure that you view things both close up and far away across your day.
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Many, many people nowadays spend a lot of time looking at their smartphone, looking at the computer screen,
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looking at books and paper, in other words, looking at things somewhere between 9 inches away from their face and their eyes, maybe 2 and 1/2 feet away
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from their face and eyes. This is an unprecedented event in human history,
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as far as we know, because it wasn't until the advent of the smartphone
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that we've spent so much time looking at screens at close range relative to looking
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at things at further distances from our face throughout the day. In fact, it should come as no surprise
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that the incidence of myopia, of nearsightedness, is increasing dramatically around the world
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but is increasing particularly fast in children and in young adults and even in adults
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who are viewing things at very close range, so 2 and 1/2 feet or less. Now, I am not saying that viewing things
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at 2 and 1/2 feet or less is bad for your eyes, that is simply not the case. However, if you want your vision to be maintained or even
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improve, it's going to be very important for you to view things at a distance as well for ideally several hours per day.
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Now, I realize some people just simply won't accomplish this. In fact, I'd like everyone to just take a moment and do a rough estimation in your head
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of how much time during your daytime activities you are viewing things at, say, 2 and 1/2 feet or 3
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feet or less, so smartphone, computer screen, paper, books, et cetera, versus viewing things
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that are 4 feet away, 8 feet away, so maybe conversation across the table with another human being.
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Remember those? Some of us are doing that more now that we seem to be emerging from this whole pandemic phase.
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However, many people are still mostly just viewing things within very close range. And, in fact, if you were to ask yourself, how much time do
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you spend looking at things at the distance of many hundreds of feet, or taking a walk where you're not looking
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at any screen and you're simply letting visual images or the visual imagery rather pass by on your eyes, I think for most of us
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that number is getting progressively smaller and smaller with each passing year. So this is an issue because the structure of the eye
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is such that the lens of the eye can move, but also that the length of the eyeball from front to back
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is actually impacted by how close or how far you happen to view things
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during the course of your day, especially during development. There's a classic experiment that I'd like to just briefly describe to you which
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has been performed in chickens. It's been performed in mice. It's also been performed on humans,
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where a visual occluder or a visual image.
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So an occluder is just a black screen or a piece of cardboard or an image, maybe some black and white checks or checkers,
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are placed at a certain distance from the eye, either up close or far away, and the impact
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of that on the length of the eyeball and on the structure of the lens and on the quality and acuity
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of vision is then measured. And to make a long story short, what these studies show is
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that, if during development, you or an animal exclusively looks at things that are up close, very
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close to the eye, and doesn't ever get long-range vision, the eyeball lengthens.
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And when that happens the lens, which, of course, is in the front of the eyeball, which focuses the light onto the back of the eyeball,
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which is where the so-called neural retina is, where the cells that sense light are, that visual image lands in front of as
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opposed to directly on the light-sensing portion of the eyeball that we call the neural retina.
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It lands too close or near the lens as opposed to
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on the back of the eyeball. And that's part of the reason what we call the consequence of that nearsighted myopia.
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In far sightedness, the opposite happens. The visual image is actually focused behind the retina.
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It doesn't land directly on the retina, which is what you want. It's focused too far behind the retina.
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And that's due to a shortening of the eyeball. So what I just described actually explains pretty well why kids who look at computer screens,
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or books up close often need glasses. When I was growing up, they called this nerd syndrome.
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Raising my hand for those of you that are listening. I read an awful lot, but I also spend time outside fortunately
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and running around on the soccer field and looking at things in the distance and playing in the neighborhood with my friends.
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Kids that spend the vast amount of their time looking at things up close, and particularly
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children who do that indoors for most of their waking time, well, those kids develop myopia.
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This is part of the reason why we have such an increase of the incidence of myopia nowadays.
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What's interesting, and I think most people don't realize, is that even as a young adult and adult, and perhaps even as
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an older adult, an elderly person, looking at things up close to much at the expense of getting
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some time viewing things at a distance, in particular outdoors, can be very problematic because it
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can exacerbate myopia. So the short, direct prescription here is to make sure that you're getting at least an hour or so
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each day, although ideally it would be more, of long viewing. And that could be done by walking outside and avoiding
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looking at your phone while walking. It doesn't require that you look at a particular object in the distance, although if you are scanning for and looking
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for objects in the distance, the way that you might on a hike or you're looking out toward or off a vista
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or you're looking for someone in the distance, all of that sort of visual scanning behavior is going to be very good for your eye health
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and for maintaining vision at a distance. If you're somebody who's far sighted and you have trouble seeing things up close,
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well, then you need to ask yourself whether or not you're spending too much time looking at things off in the distance, although I want to be very
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clear that nearsightedness and farsightedness aren't necessarily the consequence of this near, far viewing.
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There can be independent causes of nearsightedness and farsightedness. But for many people out there who
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are spending progressively more and more time just looking at things up close, you can get this lengthening
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of the eyeball or challenges in the way that the elasticity of the lens is controlled
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by the musculature in ways that make it hard to maintain sharp, crisp vision when you're
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looking at things at a distance or up close. So I can't, because there are simply no studies
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to support the idea that you need exactly two hours per day of outside long vision at a particular distance and/or
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that you want to cut off or have a threshold of four hours per day of looking at things up close, but we can say with a high degree of confidence
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that if you want to maintain or enhance your vision at all distances, that for every hour or so
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that you spend looking at things, say, a distance of 3 feet away or less,
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that you want to get at least one hour per day total, doesn't have to be all at once, of looking at things out in the distance
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or looking at things beyond 3 feet relative to the distance from your eye.
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So I think for some people who are already badly myopic, this isn't going to remedy that myopia.
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You're still going to need corrective lenses, but if you're somebody, similar to the person who asks the question, that they're quote unquote "noticing"
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their vision is deteriorating, really try and balance out the amount of viewing
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that you're doing at close distance and long distance. And, again, I would not obsess about the total numbers.
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It doesn't have to be three hours and three hours, but the more time that you can spend at viewing things
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that variable distance throughout the day, the better off you're going to be in maintaining and perhaps even enhancing your vision somewhat.
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Now, there's an additional behavioral tool that we can glean from the recent scientific literature exploring myopia which points to the fact
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that children who get two hours a day or more of time outside in sunlight--
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one of my favorite topics. I know many people are probably rolling their eyes right now when they hear me say you really
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want to view morning sunlight, not through a window or windshield. Don't wear sunglasses for that, trying to get as much sunlight
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as you can in your eyes early in the day. Never stare at any light so bright it's painful, look at, et cetera. We've done a lot of episodes on this.
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We have a Light for Health episode, this Isn't All the Sleep episodes. It's just such a basic foundation of circadian rhythm and health that I just keep repeating it.
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However, there are also large-scale clinical trials involving thousands of subjects that have shown that people, children in particular, who
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get two hours or more of outside time every day have a much lower incidence of myopia.
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Now, what's really interesting about these studies is that, while some of those kids are looking at things further
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off in the distance than they would if they were indoors on their tablets or screens or with their nose in a book,
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it does not seem to be the case that they have to be looking at things in the distance in order to see this reduced incidence of myopia.
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What's probably happening instead is that the particular wavelengths of light that emanate from the sun,
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that photon energy in particular is triggering the activation of the so-called intrinsically sensitive melanopsin and retinal ganglion cells, which we know
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are important for setting circadian rhythm for enhancing mood focus and alertness during the day and enhancing the quality and duration of sleep at night.
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But those melanopsin and intrinsically photosensitive ganglion cells are also involved in networks
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within the eye that relate to blood flow, that relate to the ciliary body, which
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is a structure within the eye that controls the aperture and movement of some key components
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within the eye, that also relate to the crispness of vision, that is the acuity of vision, at both short and long range.
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So there are a lot of technical details there. In fact, I really hope to get the great Russell Van
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Gelder, or Dr. Russell Van Gelder, who's the chair of ophthalmology at the University of Washington in Seattle, who is a world expert in this
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and the various aspects, both molecular and structural of the ciliary body and the lens,
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and he's an expert in uveitis, a very interesting topic in its own, to come onto the podcast
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and talk more about eye health. And we will do that in the not too distant future. Meanwhile, if the first behavioral protocol
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for enhancing and maintaining eye health is to make sure that you're spending at least some time balancing out the near vision and far vision during the day,
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it also stands to reason that you want to get outside for at least two hours a day, which I know sounds like a lot, in order to prevent myopia,
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if you're a young person, and offset the progression of and maybe even reverse some myopia, we don't know yet based on the data,
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but there's some indication that's possible, by getting outside two hours a day. And the cool thing is, because many people, including myself,
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have a lot of work to do and we need to be on our phones quite a lot, or we choose to be on our phones quite a lot, this effect of getting sunlight outdoors during the daytime
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for two hours or more does not seem to require that you stay off your phone or tablet,
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or that you're looking at things far in the distance the entire time. What this means is, if you can get
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outside onto a patio or a deck or an outdoor table if you can, if weather and conditions permit,
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and do some of your phone time and computer time and reading, et cetera, outdoors. Now, if you're already making an effort
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to get outside, hike, play sports, take walks, et cetera, that of course counts towards this two hour
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threshold. And I know this sounds like a lot, this two hours, and yet for most people, it certainly will vary,
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depending on time of year, but I think striving to get on average about two hours of outdoor time as much as you can or opening a window, which
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wouldn't be as good as getting outside, but opening a window and trying to get some natural light exposure to the eye to trigger the activity, these intrinsically
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photosensitive melanopsin and retinal ganglion cells, that's going to be a really good idea in trying to offset and maybe
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even reverse some vision loss. Now, the other behavioral protocols which have shown to be useful in terms of maintaining
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or improving vision relate to the musculature around the eye and the control of the movement of the lens.
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And actually, the lens of the eye has its own flexibility. It's a really, really interesting structure.
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I'll geek out on this far too long if I don't prevent myself from doing so, but the lens is just incredible.
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The fact that it has a specific structure of proteins like crystallines and things of that sort
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and that it can still derive nourishment from blood flow
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but does not actually have vasculature within it. So it's not-- if you notice the lens of your eyes and filled with blood vessels and capillaries
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because it needs light to pass through, super interesting structure I think the only violation of what I just said is the manatee.
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Those pigs are underwater, elephant-like creatures that I think were or are endangered.
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Down in Florida, they were getting chopped up by speedboats, but I think now there's some effort to preserve those big gentle giants.
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The manatee, as I recall, has a vascularized lens, which is why their eyes look opaque.
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It looks like they have cataracts. In any case, you're not a manatee.
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You have no blood vessel supply to the lens. Keeping that lens clear is vital nowadays.
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They can do lens replacement. There's really a pretty incredible progress
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in the realm of ophthalmology and surgical replacement of the lens or the cornea, other aspects of the eye.
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But if you're somebody who is interested in maintaining your vision, you're going to want to maintain the musculature that controls
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the movement and the change of shape in that lens and the movement of the eyes, which allows you to transition
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your vision from very sharp when viewing things up close to very sharp one viewing things at a distance.
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And this is where some of the so-called near-far exercises can be very useful.
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So when we did a full length podcast on eye health and improving eyesight, which I invite you to listen to if you like, talked
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about two different types of vision exercises that have been shown to be useful for improving vision
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at a level of acuity that have a lot to do with improving the musculature and the movement
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of the eyes and the lens. And that's what's called a smooth pursuit task. So you could go on to YouTube if you like and put smooth pursuit
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eye task and do this for a few minutes each day if you're trying to keep your vision strong. And what that task involves is, as the name suggests,
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smoothly tracking a small dot or crosshatch or arrow on the screen, which is very different
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than the so-called saccade type eye movements that we often make. Saccades are when you dart your eyes to a particular location
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to look at something that dart it to another location to look at something. Microsaccades are little, tiny versions of those that were doing most all of the time,
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believe it or not. When you look at a visual scene or image, if you did not have those little microsaccades,
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your brain would adapt or would attenuate to whatever you were looking at, and the visual image
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would actually disappear, which really speaks to how important it is that your perceptions change in order to maintain them.
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This is very similar to where if something is placed on your hand, say a finger, you'll notice that change, but then
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if you leave it there for a short while, you'll forget that it's there because the cells there have adapted out.
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There's no change. So your nervous system is largely responding to change. This is also why when you walk into a room and you'll often notice a novel smell,
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let's hope it's a good smell, after a few minutes or so, you don't notice the smell anymore because your olfactory system adapted that away.
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So a lot of that adaptation is prevented by those little microsaccades. And the macrosaccades, the bigger saccades,
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are really for moving your eyes around to look for things in visual space. Smooth pursuit is a very particular kind
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of visual behavior that you can do in a smooth pursuit task and zero cost. Costs a little bit of time I suppose to do this on YouTube.
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And most any of them will do. We can provide a link in the show note captions of one that we like or several that we like,
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but by doing that smooth pursuit task for a bit each day, maybe just a minute or two, you're maintaining your ability through the musculature of the eye
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to do smooth pursuit. And, of course, you do smooth pursuit when you move about your day, but for people
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that are trying to offset or reverse vision loss, doing some additional deliberate smooth pursuit exercises can be useful.
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The other visual exercise that can be very useful is the so-called near-far exercise. So this is best accomplished, I think,
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by holding out a pen or pencil in front of your eyes,
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in front of your head, and focusing very intensely through what's called a vergence eye movement, where you bring both eyes to the tip of the pen and then moving
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that pen closer and closer and closer to your eyes, where you get close enough that you actually
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have to deliberately bring your eyes-- for those of you listening, this is what I'm doing right now-- to the point where it's blurry
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and you can no longer hold it in sharp, crisp relief. You can't see it sharply that is. And then you can move it out a little bit distance
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and play right around that threshold where it's hard to keep it in focus
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and then move it back out again. And then in doing that for even a minute or two, you'll find is a bit of a strain on your eyes,
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but you can actually build up the musculature and the neuromuscular connections that allow you to do that more efficiently.
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And that has been shown to improve certain aspects of vision, especially when people are diligent about doing those exercises,
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not necessarily every day, but let's say three days a week or so. They can be very fast. I actually find them fun for reasons
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that escape me entirely. Now, how close you can bring that object and still maintain it in sharp focus
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will vary from person to person based on a number of things. First of all, how healthy and well-performing
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their neural retina is, whether or not they have myopia or hyperopia, nearsightedness, et cetera,
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whether or not, for instance, you're like me and you have a fairly close inter pupillary distance,
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or whether or not you're more wall eyed and you have your eyes set further apart. All those things will dictate the exact performance
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of that task, but nonetheless, it's a very useful task to do when trying to maintain or improve vision.
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Now, of course, there are a lot more behavioral tools that one could use to maintain or enhance vision. I'm really touching on the biggest
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and what I consider the most important ones that are most accessible to people without the need for any fancy equipment at all.
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And if you want to learn more about other behavioral tools that one can use to maintain or enhance vision, please see the episode that we did on eyesight.
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You can simply go to hubermanlab.com. Put into the search function, eyesight or vision. It'll take you right to it.
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In fact, everything on that website is keyword indexed and will take you to the various episodes and time stamps
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that you're interested in according to that keyword. Now, the person who asked this question, who by the way,
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is Page Singer, thank you Page Singer, and the question got a lot of upvotes because apparently there's a lot of interest in this,
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understandably so, asked about nutrition and supplements for maintaining or improving vision.
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That could be a very lengthy conversation, but let's just summarize it with a few brief points that we know stand based on the clinical and scientific
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research. We've all heard that carrots are good for your eyes. Well, it's not carrots per se that are good for your eyes.
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It's vitamin A that's essential for the so-called phototransduction cascade. The phototransduction cascade is the process
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by which the photoreceptors, which are in the back of the retina, at least if you're human, they're in the back of the retina,
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take photons, light energy, and convert it into electrical signals that's then conveyed to the other cells and neurons within the retina
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and then passed into the brain to create visual perceps. Most people can't get enough of this fat soluble vitamin,
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we call vitamin A, by making sure that they eat at least some dark green leafy vegetables.
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And that they do that in their closest to raw form, maybe cooked a little bit
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but not overly cooked. There are other sources of vitamin A out. There you can look those up online just for sources
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of vitamin A. Most people will be able to get enough vitamin A from their nutrition and won't require it from a supplement,
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provided that it's not present at excessively high levels in a foundational supplement or vitamin mineral supplement.
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Getting some additional vitamin A from a foundational supplement or vitamin mineral supplement
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is probably not going to be an issue unless you really take in far too much of that vitamin A. It could potentially provide some insurance.
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But, again, I think most people can get enough vitamin A from their diet if they are taking carrots or to eat the foods that contain vitamin A,
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green leafy vegetables being one. The other food that's known to be highly enriched in vitamin A is liver, one of my least favorite foods regardless
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of what animal that liver comes from. Liver is somewhat of a popular/controversial organ
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meat in the nutrition space for reasons that aren't interesting, for sake of this discussion anyway I suppose for those of you
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that like liver, you could eat a little bit of liver every once in a while. It is rich in a number of things that are beneficial to health,
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although for you vegans out there, I'm sure you'll want to avoid liver entirely. I avoid liver because I just simply don't like the way it tastes.
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Maybe once or twice I've tasted liver that was appetizing to me. And it can be OK, but it's just not, or at least by my read it,
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can be OK, but it's not a food that I actively seek out, order, or prepare for myself on a regular basis.
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So fortunately, there are other sources of vitamin A as well. And, again, I just invite you to all put into a web search food
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sources of vitamin and figure out how to get your daily dose of vitamin A by taking in foods that you like for you.
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And then in terms of supplementation of things that can enhance vision, this is a newer area.
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And frankly, it's an area where most of the data point to some supplements that can potentially
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be beneficial in certain disease conditions. So for instance, in fairly progressed age-related macular
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degeneration. Age-related macular degeneration is fairly common, or more common than we would like,
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we should say. And it does appear that supplementing with certain things like lutein, which is present in eggs,
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or egg yolks in particular, especially egg yolks that aren't overly cooked, or that can be supplemented
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can potentially help with some instances of age-related macular degeneration.
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But the data on this are still emerging. I consulted with our chair of ophthalmology at Stanford about lutein and some of the other things
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that you'll see out there, like zeaxanthin and astaxanthins. And these xanthins come from certain fruits
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like blueberries, and they're present in supplements and things of that sort. The consensus I got talking to him
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and talking to some other ophthalmologists are that if you're really aiming to get a healthy diet, you're avoiding cigarette smoking.
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And by healthy diet I mean getting sufficient amounts of vitamin A and lutein
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through food sources. Again, you can look up where those food sources are, egg yolks just being one of them.
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Well, then chances are you're not going to need to supplement with lutein or the zeaxanthins
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or the astaxanthins. However, I have heard anecdotal reports from a number of people
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that they'll start taking a supplement for eye health, there are a number of them out there-- we are not, as a podcast, affiliate
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with any of those eye health supplements by the way-- and people are reporting enhanced vision.
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I receive emails all the time that say, I'm taking this lutein at 20 milligrams per day,
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and there I should mention that the dosage that's been explored in a couple of studies is 10 to 20 milligrams per day.
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Again, you could get that from foods. You could go above that if you're more cavalier,
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or you could go toward the lower end of that, 10 to 20 milligrams per day, if you are somebody
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who's more conservative. I should say. Well, there aren't people out there who are, looking at lutein, they think it's fairly safe,
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and they're taking higher dosages of lutein, so 20 to 30 milligrams per day. They're also taking supplements that contain zeaxanthins and astaxanthins
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and are reporting anecdotally that their vision is enhanced. I don't dispute those claims, but as of now, there
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aren't many papers, I could only find about 4, 3 really solid ones and then a fourth, that point
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to the specific disease instances where supplementing with lutein, zeaxanthin, or astaxanthin
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can be beneficial for slowing the progression of things like advanced onset age-related macular degeneration.
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And the degree of offset for that macular degeneration was slight. It wasn't enormous, but it was robust enough
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that it warranted reporting in the paper. Or things like Lieber's, which is a particular eye disease.
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It impacts a whole different set of systems in the eye. So basically, what I'm trying to say is, when it comes to supplements to support eye health,
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make sure you're getting enough vitamin A from your diet. If you're not, consider supplementation or consider changing your diet somewhat
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to make sure you can get that lutein and vitamin A. And if you are interested in it, and it's within your budget,
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I don't know of any evidence that supplementing with additional lutein, zeaxanthin, and astaxanthin
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can be dangerous at all. So for those of you that are really interested in maintaining or improving your vision, that might be an area that you want to explore.
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I personally am not taking lutein, zeaxanthin, or astaxanthin, at least not at this time.
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I do take a foundational supplement, which is my source of vitamin A in addition to my food sources.
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But I don't suffer from vision loss anywhere, readers at night, and I have for a long time. I have a little bit of a muscular weakness
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in one of my eyes that originated in childhood. So occasionally, if I get very fatigued, one of my eyes
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will deviate a little bit, a little bit of almost strabismus, especially if I've been awake for very long periods of time.
27:52
It tends to recover once I get a good night's sleep. Some of you that have experienced this, where you have one eye that might just drift a little bit.
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I could do this for the camera if you want. OK, this is weird. I used to do this to my sister across the table when
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we were at a friend's houses for dinner. So I can actually move one of my eyes in like this, which actually just reflects that there's a extraocular muscle closer to my nose.
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It's rather weak, which allows me to do that. I can't do it so well with the opposite eye. Anyway, now I need to blink to clear my vision.
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But the point is that, if you're somebody who has a slightly deviating eye, slightly,
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often if you go to the ophthalmologist or optometrist, they're going to give you a prism lens which is going to redirect the image onto that slightly
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deflected eyeball. One thing you'll really want to discuss with that ophthalmologist or optometrist is whether or not
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there are exercises that you could do to overcome that issue without the need for a prism because what I saw
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and what many other people see when they put on a prism lens is that indeed it can line up their vision
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or their visual perception better, but indeed, it can lead to progressive weakening of the muscle further and further.
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So then that eyeball starts to deviate further and further. And that raises a larger question, which is, should we wear corrective lenses?
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In fact, if you go online, you'll find or hear about these examples of people that stopped wearing their corrective lenses,
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their glasses or contacts, in order to bring their vision back or improve their vision on their own.
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Now, if your vision is quite impaired, you're going to need corrective lenses or contacts. However, there are a number of people out there
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who find that if their vision is somewhat impaired, that forcing themselves to view things at a distance
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to do smooth pursuit, to do near far, and to make sure that they're getting adequate nutrition
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and things of that sort, can all sum to help offset some of the visual impairment that would
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occur if they were to just pop glasses on their face and rely on the corrective lenses
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in order to focus the light onto the correct area within the eye onto the neural retina.
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So I'm not telling people to throw off or get rid of their corrective lenses and contacts, but you can be overly reliant on these things, like a crutch,
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in a way that perhaps you want to do a little bit of work to try and overcome and then maybe work with a weaker prescription.
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And certainly, in the case of prism lenses, what I mentioned before is a real consideration. It's one I'm very familiar with.
30:07
So as a last but I think very important and exciting feature of visual improvement is red light.
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I talked a little bit about this on the episode of the Huberman Lab podcast all about light and health. There's some really spectacular, I
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think I consider it spectacular, many other people consider it spectacular, research out of University College London.
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And the work I'm referring to is Glenn Jeffrey's work. I've known Glenn for a long time. These are animal studies, and now two human studies,
30:32
exploring how exposure to red light early in the day
30:37
can offset some of the vision loss related to age-related macular degeneration, or simply
30:43
age-related visual decline. There's a whole mechanism here that's discussed in that episode, but it has to do with the fact
30:49
that red light and near-infrared light, together, or maybe even separately, when viewed for even just a minute
30:56
to 3 minutes once, or maybe two or three times per week maximum, can actually reduce the number of what
31:04
are called reactive oxygen species in the photoreceptors that convert photons into electrical signals the rest of the visual system can understand.
31:09
So that's a mouthful. Basically what they found was, for people 40 years or older,
31:16
if they viewed this red light at a distance of about a foot and a half, although I wouldn't
31:22
get too specific with this, for a few minutes each week total, they were able to offset some of the vision loss
31:28
within a particular domain of vision. And I don't have time to go into the details here because I do that in the Light for Health episode,
31:35
but you have different types of photoreceptors, cones, and rods. You have different types of cone photoreceptors
31:41
that respond to different wavelengths of light, short, medium, and long wavelengths of light so-called blue, green, and red cones,
31:48
they're sometimes called. When these people who are 40 years or older viewed red light on a consistent basis early in the day,
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and it did have to be early in the day, there was a real circadian effect there, there was a offset of some of the vision loss
32:03
that would normally occur in a particular wavelength of light range that resulted in better visual acuity overall.
32:10
So if you're very concerned about your vision, or you're into red light therapies, et cetera, there are a number of different red light devices out there.
32:18
At some future point, the Huberman Lab podcast may partner with one of these red light companies. So right now, I'm not going to mention any of them
32:25
in particular. They're prominent online. What you're looking for is a red light unit that provides red light and maybe far--
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near infrared-- excuse me-- light as well. So something in the 650 to 720 ish nanometer range.
32:40
So really it's going to look red or almost invisible to you if it's really far into the infrared.
32:45
And you'll want to view that at a distance of about a foot and a half to 2 feet. And you don't want it to be so bright
32:50
that it's painful to look at because you don't want to damage your eyes. But that's essentially what they used in these studies from the Jeffrey lab.
32:56
And they showed some pretty impressive offset of some of the aspects of vision loss in these people 40 and older.
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So that's an area that you may want to explore as well, especially for folks 40 and older. And, again, this red light exposure
33:09
had to be done early in the day. So hopefully, that collection of behavioral tools near, far, smooth pursuit, some of the discussion about lutein,
33:16
nutrition, vitamin A, supplementation, zeaxanthins, astaxanthins, getting two hours of light exposure
33:22
outside, sunlight exposure, get outside to do some of your work, and perhaps even deliberate red light exposure
33:29
for certain people can be used to offset your concerns and your action potential vision loss
33:36
and maybe even improve your vision regardless of what age you are. Everything I described is supported from the Peer-reviewed literature.
33:42
And, again, if you want to get the deep dive on mechanism and further information about dosages, please check out the episode on eyesight
33:50
and improving your eyesight and the Light for Health episode again at hubermanlab.com. Thank you for joining for the beginning
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