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Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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June 28, 2011

Seeing the Light: Why Sun Exposure May Be Good for Your Eyes

By Mark Sisson
155 Comments

Having immersed myself in all things Primal for so long, I find myself viewing nearly everything through the prism of human evolution. Is this food, activity, environmental stimulus, or social more an evolutionary novelty? If so, might it possibly conflict with or impede our pursuit of good health? Is it benign? An improvement, even?

Grok logic will only get you so far. It’ll give you a nudge in the right direction – that is, headed straight to honest inquiry and further research – but it’s not enough. You shouldn’t rest on your laurels if Grok logic suggests what you’re doing is right, and you shouldn’t make big changes just because Grok logic suggests you’re doing something wrong. Instead, use those insights to generate hypotheses, then try to explore them. Research, read, ask more questions. At least, that’s what I try to do. It’s awfully tempting to just go with conjecture (especially if it turns out to be right on a fairly regular basis!).

That little preamble was just my way of setting up yet another question with roots in evolutionary conjecture: does the avoidance of sunlight via indoor living, sunglasses, and general heliophobia have an impact on eyesight, and more specifically nearsightnedness? Going purely by Grok logic and what we know about sunlight’s interaction with other aspects of our health, I think it’s a reasonable question. To whit:

Sunlight and skin – Sunlight exposure is required for vitamin D synthesis. When UVB hits our exposed skin, vitamin D is synthesized and distributed throughout our body. Vitamin D is an essential pro-hormone, necessary for musculoskeletal health, immune system robustness, as well as protection from heart disease and cancer.

Sunlight and circadian rhythm – We need exposure to light at certain times of the day in order to regulate our circadian rhythms. Without daytime/morning light, or with too much evening light, our internal clocks – and general health – go awry.

Given those two extremely basic, widely-accepted interactions between sunlight and our bodies, coupled with the fact that the eye’s express function is to interact directly with light, I think Grok logic regarding the sun and our eye health might be onto something. But we can’t be sure, remember, without confirming through other sources.

So let’s look into those other sources.

I’m sure you’ve heard of myopia. You may have it yourself or know someone who does. In case you don’t, myopia is nearsightedness, which is characterized by blurry vision when looking at distant objects. If it weren’t so easily countered with prescription eyeglasses, myopia would probably be classified as a public health epidemic. It’s that common, and it’s getting worse.

In fact, the latest statistics indicate that 41.6% of Americans aged 12-54 suffer from myopia, way up from 25% in the early 1970s. That’s an awfully big percentage of the tribe that can’t throw a spear, shoot an arrow, spot prey, or see the enemy coming from afar. That’s a ton of squinters who require assistance. In other words, if myopia were just an unfortunate part of growing old (to the ripe old age of 12!), we probably wouldn’t have made it this long.

No, there’s probably an environmental component to the rise of myopia. Genetics could play a part in determining susceptibility to myopia, and probably do, but an environmental factor is likely to be a trigger for the “myopia gene’s” expression. Could sunlight be just such an environmental factor?

Kathryn Rose, a visual disorder researcher, thinks so. First, she points to the weak or inconsistent epidemiology that attempts to link time spent on the computer, watching television, reading, and studying to the development of myopia, instead suggesting that the real problem is lack of sunlight. In cases where digital media usage or inside work appears to be associated with myopia, Rose thinks it’s actually a measure of displaced outdoor time.

Then she points toward the epidemiology exploring the link between time spent outdoors and myopia prevention, which is much stronger. Let’s take a look at a few studies:

In Chinese school children, myopia progression was inversely correlated with outdoor activity.

Near work (studying, reading) did not correlate with myopia progression, but American kids who played fewer sports outdoors had more myopia.

In Taiwanese rural children, outdoor activities might be “an important protecting factor for myopia.”

In teens from Singapore, outdoor activity appeared to protect against myopia progression.

Parental myopia status interacts with risk, too, though. In one study, kids with two myopic parents were at the greatest risk of developing myopia themselves, more so if they did not engage in outdoor sports. Kids with no myopic parents and who played a lot of sports outside had the lowest risk. Genetic predisposition expressed by an environmental trigger, anyone?

Of course, any good Primal thinker knows that epidemiology, like Grok logic, only goes so far. It’s certainly interesting, and it can inspire new avenues of inquiry, but science cannot live on epidemiology alone. You need something else to look into, like perhaps a physiological mechanism. Rose’s proposed mechanism was retinal dopamine, a “known stimulator of eye growth whose release is stimulated by light.” A lack of retinal dopamine – from avoiding the outdoors – means excessive eye growth. This is bad, for the eye is a delicate, extremely complex structure with many components, and a lot can go wrong if those components grow faster and bigger than they’re supposed to grow. Like the progression of myopia, which is characterized by excessive eye growth.

But wait – isn’t excessive amounts of light one of the big issues with modern living? Even if we stay indoors most of the day working, browsing, or watching TV, we’re still parked in front of a screen beaming light into our eyes and we’re still immersed in artificial overhead lighting. If all that light is enough to disrupt our circadian rhythms and ruin our sleep patterns, why isn’t it enough to stimulate retinal dopamine release?

It’s the magnitude. Try looking up at the sun in the afternoon. I mean really give it a good, long look. You can’t do it (in fact, that is definitely bad for your eyesight!) for more than a second or two, tops. If you squint, you might make three. Now try the same with an illuminated lightbulb. It’s easy and nearly painless. It doesn’t compare. To quantify the massive gulf between sunlight and artificial light, let’s look at another study. Researchers trying to study the link between light exposure and myopia exposed chicks to various amounts of light. Normal laboratory lighting was 500 lux, “intense” laboratory lighting was 15,000 lux, and sunlight was 30,000 lux. Only intense lab light and sunlight were able to retard the development of myopia, while normal lab lighting – which is still quite bright and very similar to standard office lighting conditions – did not adequately protect. Oh, and good news for you sunglass wearers: the chicks who were continuously exposed to bright lighting while wearing “translucent diffusers” also showed resistance to eye lengthening and myopia.

To get an idea of how many lux you can expect to “get” in various situations, check out the Wikipedia article on the subject. Prepare to marvel at the insane brightness of the outdoors and the comparatively piddling illumination found indoors. Note that direct sunlight is ridiculously bright (up to 130,000 lux), while just being outside in “full daylight” will provide plenty of light for your retinal dopamine labs. No need to stare at the sun or avoid dark forests. Just be outdoors and the sun will take care of the rest. If you can see stuff, that means light is getting to your eyes, it’s from the sun (and thus bright enough) and you’re good to go.

Of course, us oldsters might be too far gone for sunlight to have an effect on nearsightedness. Myopia develops early (hence the inclusion of 12 year-olds in myopia statistics), so it’s absolutely crucial that kids get plenty of time outdoors. I’d say “as much as possible,” but if you want a specific number, Kathryn Rose suggests between 10-14 hours a week as a bare minimum. Barring that, I suppose you could blast your toddler in the face with a halogen bulb every couple hours. No, but really: let those kids get outside, get dirty, play with bugs, climb stuff, and get some sun. Although the chick study showed that sunglasses may not be problematic, I don’t think kids need ’em, and they might still interfere with normal eye development. They’d just fall off, anyway, unless you hooked the kid up with some Horace Grant-style goggles.

Given all that, I think it’s safe to say that sunlight exposure probably plays a role in the development of nearsightedness. It’s not the only player – physiology is rarely that simple – but it appears to be a major factor. Anyway, I think we’ll have a better idea in the coming years. My Pubmed trawling pulled up a ton of very recent studies on the subject, all in the last few years or so, so we can probably expect more definitive answers in the near future.

Are you nearsighted? Did you play a lot outdoors as a kid? What’s your family history of myopia – do your parents have it too? Let me know in the comment section!

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155 Comments on "Seeing the Light: Why Sun Exposure May Be Good for Your Eyes"

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Lauren
5 years 2 months ago

Interesting. I have terrible vision, but am also very sensitive to light.

Primal Toad
5 years 2 months ago
“You shouldn’t rest on your laurels if Grok logic suggests what you’re doing is right, and you shouldn’t make big changes just because Grok logic suggests you’re doing something wrong. Instead, use those insights to generate hypotheses, then try to explore them. Research, read, ask more questions. At least, that’s what I try to do.” I am with you 110% here Mark. Its how I do things. I form a hypothesis based on evolution and then experiment on myself. My latest experimentation is raw cheese from grass-fed cows milk. Unfortunately even a little bit seems to give me acne. I… Read more »
Elisabeth
Elisabeth
5 years 2 months ago

We’re casein free at our house. It’s the protein in milk that gets my husband and daughter. Parmesan cheese seems to be my husband’s personal kryptonite, he gets some in a dish, and he’s got chills, hacking cough, and fuzzy brain for several days.

Morgan
Morgan
5 years 2 months ago

Everything grok did and benefitted from does not apply to everyone today. I eat yogurt on an almost daily basis and my skin has always been perfectly fine. I know many other people who eat cheese and yogurt well into their 30s and 40s without any issues at all. N=1 in your case.

Primal Toad
5 years 2 months ago

I said… “most of us are lactose intolerant.” Right? Oh, yea, I did.

That would be 50.00000001%. I think the number is around 75%. I may be fine with yogurt because of the probiotics and semi low lactose content. I am not sure.

I may still be fine with cheese. I mean, it could have been something else that caused the 2 whiteheads. I’ll never know for sure.

N=1 in everyones case. We are all different and thus need to experiment on ourselves to figure how we are different.

Morgan
Morgan
5 years 2 months ago

Didn’t mean to sound like I was attacking you, I was more so attacking the idea that everything grok did was best for all of us, which I believe is a bit too pervasive around here.

Primal Palate
Primal Palate
5 years 2 months ago

Remember if it’s store bought, pasteurized yogurt, clabber, buttermilk, you name it…there is puss and blood in it, too.
It’s a toxic soup that has to be pasteurized because of the conditions and health of the cows and the enviroment they stand in, regardless if it says ‘organic’.

Most people are allergic to that toxic soup, not the actual lactose. Unless you have a test done, there is no need to assume you’re allergic to lactose…dead bacteria mimic a virus that your body tries to get rid of, too.
There are many, MANY reasons you ended up with white heads.

Omnomnivore
5 years 2 months ago

On bright sunny summer days, sunlight hurts my eyes. Not looking at the sun, just being out in it. I look terrible in hats, but it beats painful squinting.

I have one nearsighted eye and one farsighted eye, which is the same as my mother. They compensate for each other very well, and I don’t need to wear glasses (though I did from age 12-17). I played outdoors a lot as a child, but bright sun has always been pretty uncomfortable.

Jeanna
5 years 2 months ago

I love the sunshine… it makes me feel better all over 🙂

Primal Toad
5 years 2 months ago
They’d just fall off, anyway, unless you hooked the kid up with some Horace Grant-style goggles. Oh boy… I remember Horace Grant from the Chicago Bulls – MJ days! He played for the Charlotte Hornets too, didn’t he? Sunlight also hurts my eyes. And, if I am indoors for a while, say an hour or more and go outside in bright sunlight then I always sneeze immediately. Usually twice. I do not have allergies of any kind and never have. I just always sneeze when going from a dark room to bright sunlight. Does anyone else do this? My father… Read more »
Deb
Deb
5 years 2 months ago

Wow! yes I too sneeze when going into bright sunlight. No other known allergies except to wheat.

Harry
5 years 2 months ago

Yes, sunlight makes me sneeze too. More so when I was younger.

Stephen
Stephen
5 years 2 months ago

Yup, me too. No one ever believes me that it will happen until I show them. I read somewhere that it is a protection mechanism to prevent you from looking at the sun too long. Many people will sneeze if you ask them to look almost directly at the sun, but I guess some of us are more sensitive. Incidentally, I have no vision problems, coincidence?

cTo
cTo
5 years 2 months ago

It’s actually a genetic allele, whether people do this or not.

Primal Toad
5 years 2 months ago

Ha, glad to see others are in the same boat as me. I will add that sometimes I go out in the sun and I kind of have to sneeze. If I look up at the sun or face towards it then the sneeze comes on even more and then BAM! I let it out.

Its not just sunlight either… it can actually happen in side with artificial lights.

Alex
Alex
5 years 2 months ago

Sneezing caused by bright light is a common thing. It’s thought to be a result of cross-talk in the nerves when the optic nerve gets overstimulated (bright light) and some of that signal stimulates the trigeminal nerve that runs right near it.

Morgan
Morgan
5 years 2 months ago

you have lighter eyes right? I think this happens more often with people who have ligher eyes. My eyes are green and I can sneeze when I first look into the sun after being indoors for a while. When I was young, I would wake up to use the bathroom at night and sneeze from exposure to the bathroom light.

Erin
5 years 2 months ago

I totally sneeze from bright sunlight, bright snow and lightbulbs. If I need to sneeze but can’t quite, I just look at a lightbulb;) It’s an inherited trait. My dad also does this.

PrimalGrandma
PrimalGrandma
5 years 2 months ago
I, too, will sneeze right when going out into the bright sunlight. I’m almost 67 years old and it’s been something I’ve done all my life and still do! If I get up at night to use the bathroom, same thing – I’ve learned not to look in to the overhead light otherwise I’ll sneeze my head off! By the same token, have you ever felt like you needed to sneeze – maybe something like dust or whatever was up your nose but you couldn’t quite get past it? Well, all I have to do is look at a bright… Read more »
MamaGrok
MamaGrok
5 years 2 months ago

Sunlight doesn’t make me sneeze by itself, but if I find myself feeling like I need to sneeze, I’ll look to the sun and it always helps me out! Bright indoor light isn’t as quickly effective, but will do in a pinch.

My husband thinks this is nuts. Now I can tell him why!

Elisabeth
Elisabeth
5 years 2 months ago

It an example used of simple Mendalian inheritance. It is dominant. I learned it as Achoo syndrome, but the fancy name is now “Photic Sneeze Reflex”.

According to Wiki, the condition affects 18-35% of the human population.
The first mention of the phenomenon is probably in the later work attributed to Aristotle(between the third century BCE to the 6th century CE).

And yes, I sneeze when I suddenly step into bright lighting too. 🙂

Primal Toad
5 years 2 months ago

Very interesting indeed! So about 1/4 on average I guess. Cool camp of “buttercups.” -Robb Wolfs favorite word.

fritzy
fritzy
5 years 2 months ago

I wonder if you can have a mild form of this if you are a “carrier” of the gene. If I need to sneeze, I look at a bright light to help it happen but I don’t sneeze just from looking at a bright light. Very interesting stuff.

Morgan
Morgan
5 years 2 months ago

Sunlight feels great on my eyes, so good that I actually used to enjoy looking into it feeling no or little discomfort for quite a long time(i know this was bad). I have green eyes and also sneeze when looking at the sun after being indoors for a while. When I was young it I would sneeze just after turning on the light to the bathroom during my nightly middle of sleeptime visits.

Melody
Melody
1 year 4 months ago

Sungazing is an ancient practice that is potentially very good for our eyes and general health 🙂 Though it is usually done within an hour of sunrise or sunset to get a lower dose of light.

2Rae
2Rae
3 years 2 months ago
Both my son and I sneeze when we go from dark to light. I assumed that it was due to the release of moisture from my eyes that seem to drain into my sinus. That tiny bit of moisture is enough to make us both sneeze. That’s also what makes my nose run (tears) when I go from warm to cold or from cold to warm. So I carry hankies everywhere I go. My dad used to say regarding food “it’s not good unless it makes your nose run.” Ahahahahaha, I guess it’s a family thing.
Melissa
Melissa
5 years 2 months ago
My dad had perfect vision, but my mom is practically blind without glasses. By the time I was 7, I had glasses to correct nearsightedness, and have worn glasses or contacts my entire life. I heard a theory once that prior to WWI and WWII, there were less people who needed glasses, but that military service and many deaths essentially helped cull good vision out of our “herd”. Men with bad vision weren’t accepted into the military at that time, so they stayed home and made babies while men with good vision went abroad and got killed. Not sure how… Read more »
Melissa
Melissa
5 years 2 months ago
I would also assume, evolutionarily speaking, that before the invention of glasses, people with myopia would have had less of a chance to procreate. What self-respecting Grokina wants to be saddled with the mate who can’t hunt or even gather? Since myopia is no longer detrimental to mating (for which I’m selfishly glad!) the genes would get passed on a lot more. (I wonder though, if slight myopia would be an asset for working with your hands? I know that I am able to focus more closely to my face than people with normal vision, possibly there was at one… Read more »
MamaGrok
MamaGrok
5 years 2 months ago
Just another theory from conventional wisdom that assumes that primitive man had just as many plagues as modern man (that is, every man has two or three major ones!), but that natural selection kept the plagued from breeding. The theory is that it’s all genes. No, it’s genetic expression. Our modern diet & environment are distorting our genetic expression. Genes determine who among those with bad environmetal factors will develop what ailment. Myopia is connected with insufficient sunlight, excess carbohydrate intake, & excessive near work. It is nearly 100% preventable if you are somehow able to avoid those factors.
john
5 years 2 months ago

Retina illumination causes retinoic acid synethesis.

http://www.pnas.org/content/93/22/12570.full.pdf+html

Last summer I got tons of FL sunlight and ate much liver. Upon going back to NJ and an office, I developed a very slight visual problem (sensitivity to car lights at night) after 6 weeks. I was still eating liver but instead of sunlight, I was supplementing D3. I’m still trying to figure out what’s going on–it’s a little better.

Deb
Deb
5 years 2 months ago
Started wearing glasses when I was 12 years old. I was born in 1951 and played outdoors most of the time when weather permitted. My father had myopia at about the same age, he was born in 1923 and spent very little time indoors. Mother had perfect eyesight until she reached her mid 50’s. Older brother has myopia, started wearing glasses at age 10 years, also spent a lot of time outdoors. Younger brother, perfect eyesight until mid 50’s. My son has perfect eyesight and hardly every played outdoors, my daughter has myopia from about age 12 and played outdoors… Read more »
Uncephalized
Uncephalized
5 years 2 months ago

In your case, maybe not. Seems like your dad passed on some pretty bad eye genes. Doesn’t mean it’s not true for others, though. And who knows? Your vision could have been even worse…

Morgan
Morgan
5 years 2 months ago

Why did your son hardly ever play outdoors? Just curious, I think things like this are interesting, especially when a boy does not play outdoors.

Obviously genetics plays the largest role here. Your experience is one family out of millions, it doesn’t mean anything.

Deb
Deb
5 years 2 months ago

He liked to play on the computer, he now works for Bioware designing video games.

WS
WS
5 years 2 months ago
From my experience(actually my brother’s), I would argue sunlight was a much less significant player. My brother and I spent equal time outside growing up. My eyesight at 40 years ols is 20/20, but he was in glasses in his teens, then contact lenses, and a few years ago corrective surgery (LASIC ?sp?). In his case, genes seem to have had a bigger impact on his eyes. That being said, my two year old daughter is outside as much of the day as she can be given the Dallas temps this summer. I think its important for a number of… Read more »
Mark Luedtke
5 years 2 months ago

I read a study a lot of years ago that correlated myopia to young children sleeping in light at night. Nightlights were a culprit.

Lord knows I spent plenty of time playing outside. Neither parent had myopia. But I didn’t have a nightlight, and I had bad myopia.

Mark Luedtke
5 years 2 months ago

I wrote that wrong. I DID have a nightlight.

Karen
Karen
5 years 2 months ago

They later learned that myopic parents tended to leave the light on in the kids’ rooms so the myopic parents could see at night. Myopic parents beget myopic kids. The nightlight had nothing to do with the kids’ myopic progression.

Mark Luedtke
5 years 2 months ago

That’s interesting since neither of my parents was myopic. In fact out of my extended family, only one other cousin, out of several dozen relatives, was.

Mark
Mark
5 years 2 months ago

I heard in a Robb Wolf podcast that grain consumption that causes an autoimmune response has a causative effect on myopia.

Sarah
5 years 2 months ago
My sisters and I played outside a LOT, however we lived north of 60 and for half the year, there was no light to play in 5 out of 7 days of the week (as we were in school, under fluorescent lights). During the summer we were outside almost constantly though, and had strong daylight the entire time. It would be interesting to see if latitude and school time have any effects in studies. That having been said, I’m only barely myopic at nearly 40 and don’t wear glasses regularly. One of my sisters is the same, the other has… Read more »
Evelyn
Evelyn
5 years 2 months ago
I think you have to include the declining amounts of Vitamin A in the form of Retinol and lower Omega 3’s and higher Omega 6’s into consideration. I certainly think we overdo sunglasses and staying indoors but I know as a kid I was always the one with my hands in the butter dish and I practically survived on egg sandwiches for years at a time and I was the only one of my siblings (4 other girls) who hasn’t ever needed glasses or braces. My mother has always had horrible vision and had horrible teeth, now my father had… Read more »
Ali
Ali
5 years 2 months ago
My mom has trifocals, my dad is legally blind without his glasses, my sister is nearsighted and has astigmatism (sp), and I am nearsighted. My brother (has a different father) does not need corrective lenses. I have to other sisters (different mother), they both are nearsighted. I have another brother (also a different mother) who does not need glasses. Time spent outside? I would venture a guess that my two brothers spent the most time outside “being boys,” but I do think I spent a fair amount of time outdoors. My husband has perfect vision. He spent a lot of… Read more »
Mustafa Korkut
5 years 2 months ago

Hello, I think it is not only the sun, but the outdoor activity. Because in those researches, outdoor means, not the city , but the great outdoors, objects far away, big blue sky, so that the eyes can rest. My wife cured her eyes with intense outdoor landscape viewing when she was a teenager. So go out ! 🙂

A.K.
A.K.
5 years 2 months ago
I am very, very nearsighted. When people who boast a -2 diapoter Rx tell me they are “blind as a bat” I want to hit them–my most current Rx had me at a -7 in both eyes, and I wear large, chunky black frames specifically so I can find them if they fall off; otherwise they’re lost in a blur. Having worked in optics for a few years in college, I’ve seen people with worse prescriptions…but not many and rarely in people as young as I am. About all I can say is that I don’t have an astigmatism and… Read more »
Trevor
Trevor
5 years 2 months ago

I hear what you are saying. I’ve had corrective eye wear since I was 8 and that’s 30 years now. And without them I can’t see closer than a few inches from my nose.

I wonder if there are any studies on glasses vs. contact lenses on how much they block the eyes of sunlight.

A.K.
A.K.
5 years 2 months ago
I don’t know about sunlight, though doctors will tell you that UV blocking is important in tinted lenses. This makes good intuitive sense: your pupils dilate when they’re in shade, which means if you’re not compensating for the increased UV exposure, you could do damage to your eyes. Either let your pupils constrict, or wear UV protected lenses to compensate. Sensible. You’d be surprised how often I sold sunglasses and had people try to haggle me out of the UV protection on the lenses to save a few bucks (no company I know of will sell tinted lenses without UV… Read more »
Melissa
Melissa
5 years 2 months ago
I know what you mean about people who think they’re blind! My most recent prescription has me at -7 (R) and -9 (L). On the rare occasion that I wear my glasses to work rather than contacts, people are shocked at how thick and distorted they are. I too wonder whether wearing glasses made my eyes worse, but if I couldn’t read the blackboard from my desk at school at the age of 7, they were probably necessary. I did notice that when I stopped wearing glasses and started wearing contacts my eyes became a lot more sensitive to sunlight.… Read more »
A.K.
A.K.
5 years 2 months ago
Do you have blue or green eyes? People with blue or green eyes tend to be far more photosensitive than people with brown eyes, whether or not they also have a vision issue. Your comment that the sun seems “brighter” with your contacts on is something I heard all the time. It’s well known. Lenses, even untinted ones, are not truly clear. There’s some distortion you have to “look” through and that provides some small amount of “shade”, or so one of the docs I worked for said. It may not be much, but eyes are very sensitive. It can… Read more »
kerrybonnie
5 years 2 months ago
I definitely wonder if eye colour has any influence. My father still has perfect vision, while my mother is mildly myopic. Out of 4 siblings, my brother who has very light blue eyes, and myself with light green eyes, both ended up myopic too. My other 2 brothers, one with dark blue eyes, and one with brown eyes, both have perfect vision. Or maybe that’s just genetic pot luck. Having lived in Australia, where the light is sheer and stunningly bright, I’ve been schooled in the importance of good sunglasses. However, now that I’ve returned to Ireland, and it’s Summer,… Read more »
Melissa
Melissa
5 years 2 months ago

I have green/blue eyes. Maybe I am more photosensitive than others. *shrug*

stephanie
stephanie
5 years 2 months ago

Sadly I am one of those in the minority with an even worse prescription than you. I get jealous of people with -7 prescriptions who are actually candidates for LASIK. My current contacts are -11 and -11.5 glasses are usually 1-2 diopters lower. I started wearing glasses at age 8 and have been in double digit prescriptions since High School 🙁 Both parents have excellent vision excepting mild presbyopia. One sister has perfect vision and one has a moderately high prescription.

A.K.
A.K.
5 years 2 months ago

OUCH. You have my sympathies.

Mark Luedtke
5 years 2 months ago

I feel for you. I used to be that bad in high school, college and my 20s too. In my 30s my eyes started getting better. I’m -9 now. It’s amazing how much of an improvement that is.

If the nightlight wasn’t the cause, I have no idea what it could have been. I didn’t eat or play any different than anybody else in my family. We were outside playing all the time. And we don’t have a history of myopia in the family.

Mark Luedtke
5 years 2 months ago

My eyes are green. Maybe light eyes in the sun too much as a child?

lyra
lyra
5 years 2 months ago

Years ago, an eye doctor told me that a high fever in early childhood can lead to high myopia later on. He said that was often the case when parents with normal vision had a child that was a high myope. Something to do with collagen formation.

Anne
Anne
5 years 2 months ago

What about the possible role of vitamin D? Less time outside may also mean greater vitamin D deficiency. Or perhaps those with myopia cannot use the vitamin d they have? http://www.ncbi.nlm.nih.gov/pubmed/21357399

Jim
Jim
5 years 2 months ago
My vision changed when I was in high school, and I’ve worn glasses or contacts ever since. Most folks with myopia see a generally slow and steady decline of their vision over the years, but mine has remained essentially unchanged for about a decade, and the changes before that were minimal. (A lot of my peers are getting bifocals and reading glasses, meanwhile.) Yes, I feel lucky to have kept my vision stable, but wonder how the sunlight theory would fit? Can it help maintain vision once it’s degenerated to a certain level? I am also very fair and sensitive… Read more »
Matt
5 years 2 months ago
I developed myopia in grade 7 and when I was in grade 9 I started to do as much research as I could about the causes. Like you I realized that if 40% of the population can’t see well without glasses then as a genetic trait is should have disappeared long ago. My physics teacher in high school taught at a rural school in Africa for a number of years and told us a story about how he was fascinated that none of the kids wore glasses. So he tested them all.. not one had poor eyesight, and many could… Read more »
Jesse
5 years 2 months ago

Great info, one question though:

What about those of us with blue eyes? Mine are particularly light blue almost grey in some light…but they’re extremely sensitive to bright sunlight.

This doesn’t stop me from being outside whenever possible, but it means that I wear sunglasses most of the time (when I remember them anyway).

Ginger Thickbeard
Ginger Thickbeard
5 years 2 months ago
I have my doubts about the validity of this… in my opinion genetics are the determining factor. As a boy, I spent the vast majority of my time playing outdoors, and yet ended up with glasses by the age of 7. My current Rx is -5.5 and -5 diopters, and I am convinced that if not for corrective lenses, people with eyesight as bad as mine would not be able to properly take care of and fend for themselves in this world. It’s simple: Grok’s brother Grolk, with very poor vision, had a far greater chance of perishing due to… Read more »
DeyC3
DeyC3
5 years 2 months ago

I doubt that hundreds of millions of years of successful eye evolution could be undone by genetic drift in a few decades.

Laura
Laura
5 years 2 months ago
I also have terrible eyes, and have worn glasses since 2nd grade. My mother’s are worse than mine, but my father’s are better than 20/20. I definitely lost the genetic lottery there. Tons of time spent outside as a kid, and I wouldn’t even wear the (prescription) sunglasses, despite my father’s nagging. Many is the time that I reflected on how lucky I am to live in an age with corrective lenses, lest I be eaten by a bear, or a useless burden on my family. I recently read an article (over at Archevore, I think) which said that the… Read more »
Peggy The Primal Parent
5 years 2 months ago
Just this weekend I read on another blog a study linking our time spent indoors and myopia. That’s a tough one for me to swallow. I spent nearly all of my time outdoors as a child. I had a huge backyard in California and my parents were in their 40s so they pretty much left me to play outside with my brothers all day every day. I was severely nearsighted by the time I was 10. My brothers and sister had absolutely perfect eye sight. I had celiac disease too which none of them seemed to have developed. I was… Read more »
DeyC3
DeyC3
5 years 2 months ago

It is my understanding, as per science magazine blurb circa 10 years ago, that myopia is caused by insulin levels in childhood and has been on the rise for 300 years following the trend towards increasing refinement of carbs. That myopia has increased so much since the Lipid Hypothesis caught traction suggests that, indeed, a lowfat, high-carb diet is to be implicated. For too many reasons to get into here (including Global Dimming), I think sunlight is barking up the wrong tree.

Tim
Tim
5 years 2 months ago

This is an example where correlation is being confused with causation.

An alternative hypothesis is that kids who are myopic don’t enjoy outdoor sports and activities so much, so tend to spend more time indoors playing with things close up.

All epidemiology tells you is that An and B tend to occur together – not that A causes B. Instead, B may cause A.

Margaretrc
Margaretrc
5 years 2 months ago

Yours is, indeed, another plausible hypothesis, and you are totally right that we can’t jump from correlation to causation. It would be interesting, however, to compare incidence of myopia in tropical versus more northern climes. It wouldn’t prove anything, but could either support or disprove the hypothesis.

Kate
Kate
5 years 2 months ago

I completely agree with this article! I went for about a year of wearing no sunglasses while driving, used natural light as much as possible, and tried to stay away from the computer as much as possible (that’s hard when you are a graphic designer!). After that year, my eyesight actually improved quite a bit. I didn’t change any other factors like diet or exercise, so it has to be the wonderful sun! Great article.

Matthew Muller
Matthew Muller
5 years 2 months ago
NATURAL VISION IMPROVEMENT!! Sorry I had to break out the caps lock on that. I used to be moderately nearsighted -3.5 diopter 20/ 400 I think, and my wife told me about a book. Natural Vision Improvement by Janet Goodrich. I am not sure if it is still in print but I did the exercises in the book as well as other NVI type exercises I found via the “Bates Method” or Thomas Quackenbush. (good luck being a doctor with that name) and have improved my vision to about 20/40. The last bit has been stubborn. Essentially it comes to… Read more »
cTo
cTo
5 years 2 months ago

Iiiiiinteresting. I’ve been dealing with anxiety-related issues since college, and my eyesight (which was myopic but stable during college) has been steadily plummeting during this entire time. Additionally, I have been dealing with issues of excess muscle tension in other parts of my body, also related to anxiety.

Hmmmmmmmmmmmmm….

Isis
Isis
5 years 2 months ago

I read somewhere on the internet there is a similar YOGA technique involving palming which promotes better vision…

Alex
Alex
5 years 2 months ago

I’ve always thought that eyesight deterioration might also be related to the time we spend focusing on nearby objects.

It seems that “time spent outdoors” doesn’t necessarily pinpoint sunlight as the active ingredient; the outdoors imply both brighter light and larger focus depth (on average).

Are there any studies separating the two elements, e.g. a study showing that reading outdoors does not affect eyesight?

Primal Palate
Primal Palate
5 years 2 months ago
“I’ve always thought that eyesight deterioration might also be related to the time we spend focusing on nearby objects.” That’s what I thought. I think it’s true because my vision was fine until I started to do massive online gaming (shush…all of you lol). I don’t online game anymore but I still do research every day. I also had a computer job for many years contributing to the problem. I stopped wearing my eyeglasses for neasightedness because it can cause the retina to detach from the eyeball and cause blindness. I don’t even miss my glasses, I see fine, and… Read more »
Karen
Karen
5 years 2 months ago

Agreed. If you are outdoors, you can’t help but look into the distance at least some of the time.

PJ McNiel
PJ McNiel
5 years 2 months ago

I used to play outside all the time. It’s only in the last 5 years that I found out I was nearsighted. I did however go through that whole “it’s the 90’s, I’m grunge, I’m depressed, and I want it to rain all the time” phase (which actually lasted until I was like 35). I spent a lot of time avoiding the sun because pasty white is the new tan. Or so I thought.

Primal Palate
Primal Palate
5 years 2 months ago

Sunshine makes me HAPPY! 🙂

Steph
Steph
5 years 2 months ago

Only started wearing glasses in my 30s, and it was for farsightedness…which, oddly, makes computer work (my dayjob) hard (hm!).

I can actually still see fairly well, I just get headaches if I stare at computer screens too long. On weekends I don’t bother with contacts unless I intend to watch a lot of TV or play on the computer…and I usually don’t. I’d rather be outside or reading a book (which doesn’t require glasses) than doing what I do in my dayjob. 🙂

GymyGym
5 years 2 months ago
An issue like this gets pretty complicated. On the one hand if the statistics are truly accurate, then there is obviously some social factor at large which is contributing to the general increase in myopia. Does this effect certain geographic regions however? It would be tough to really make the conjecture that people are spending more time in-doors that lets say 50 years ago. Personally I developed myopia when I was twelve, spend almost all my time outside, my parents are big nature buffs, and that obviously didnt make a difference in my vision impairments. There are so many factors… Read more »
Nion
Nion
5 years 2 months ago

I grew up in farm country in NZ and spent a huge amount of time outdoors playing in the dirt, but my eyes suck 😛 But it runs in the family and we had poor nutrition too.

healthyengineer
5 years 2 months ago
I think there’s too many confounding effects here to isolate sunlight as the main reason why spending more time outdoors correlates with less myopia, and why the rates are increasing. The eye appears to regulate it’s own growth… by generating varying growth hormone levels in response to focus. In our natural environment, we would have had much less opportunity for up-close focusing, so the system evolved to operate in an environment with predominantly distant focusing. If instead your dominant activity is up-close focusing, this system cannot regulate eye growth correctly. High insulin levels from a high-carb diet also seem to… Read more »
DeyC3
DeyC3
5 years 2 months ago
Glad to see the insulin link. If hyperinsulinemia is warping lens development, those who were spent more time active outdoors would be expected to be less susceptible to the same high carb diet. Perhaps this also explains the rise in the glasses-IQ association–a strangely intuitive but false stereotype that psychologists have struggled to explain. Sunlight may play a role but I think it is far more likely that time indoors means time spent reading or playing video games instead of running and playing outside. And since everyone in The Zoo is suffering from excessively carb-rich diets, exercise will show a… Read more »
Karen
Karen
5 years 2 months ago

These studies showed that statistically the kids who spent more time outdoors were less nearsighted. Any one person may still become nearsighted no matter how much time spent outdoors, but on average, fewer will become so.

nbongo
nbongo
5 years 2 months ago

Both of my parents have perfect eyesight, as does my sister. Despite an entire life spent outdoors (in TX), but habitually reading anything I could get my hands on since 4, things started going blurry for me in high-school, but I’ve remained at 3.25 since then. I’m staying away from corrective keratome procedures, as it’s still too “new” to log long-term effects, for my comfort.

AnnieC
AnnieC
5 years 2 months ago
My family seems to be the exception to this theory. I have six siblings and two parents, ranging in age from 43 to 82. I note this because, as children, all we ever did was play outside. After all, there was no such thing as cable TV or any other electronic distractions. Even in the winter, we were outside in the snow. My father worked as a landscape contractor for 30 plus years, and most of us worked with him during the summers. Eight out of nine of us have required vision correction. I used to wear -10 and -12… Read more »
Gary Deagle
5 years 2 months ago

I played a lot outside as a kid. One of my eyes is near sided and the other is far sided. Its kind of crazy.

ottercat
5 years 2 months ago

wonder how much it has to do with only having to focus on things within a 20ft (or smaller) radius when you’re indoors all the time.

SuzieP
SuzieP
5 years 2 months ago
After discovering that my niece and nephew had been in a foster home for 2 years I took them both into my home. At the ages of 6 and 3 they had spent all their lives with a junk food diet, computers, TV’s, Gameboys – anything to keep them quiet – firstly by their parents and then their foster carer. Luckily both children were ‘skinny’ but their other problems started to add up – the 3 year old was in 12-18 month clothing, who couldn’t get warm, couldn’t walk more than 100 yards before becoming exhaused and the 6 year… Read more »
Emily
15 days 21 hours ago

That is awesome! 🙂

GWhitney
GWhitney
5 years 2 months ago

Yes! Which is why it’s a bit unfortunate that there are several photos of you wearing sunglasses – and Richard Nikoley too.

Hal
5 years 2 months ago

I think there’s a much larger genetic component as opposed to an exposure component. For example, people within the LDS religion have what I would consider an abnormally high incidence of eyesight issues – I’ve never seen more children in glasses than in SLC.

Lia
5 years 2 months ago

Very interesting. I am definitely outdoorsy and played a lot outside but I’m still very nearsighted.

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lyra
lyra
5 years 2 months ago

I am extremely nearsighted, and I played outside constantly (and mostly barefoot) as a kid. I was also fed properly. I have one myopic parent and one with normal vision. I’m inclined to agree more with Loren Cordain on this one — I think it’s something to do with sugar and carbs making IGF-1 levels surge, which in turn elongates the eyeballs. Combine that with some genetics, and you have a perfect setup for myopia.

Margaretrc
Margaretrc
5 years 2 months ago
I am nearsighted–became that way at the age of 21. Lived in the tropics and had plenty of sun exposure until age 18, at which time I arrived in the Northeast of this country for college. Needed glasses within 3 years–coincidence or not? It was about the same age as my father first needed glasses for myopia. Interesting hypothesis. My daughter is severely nearsighted–since before age 7. I didn’t consciously keep her from going outside to play, and she did, but she also was and is a bookworm and spent a lot of time indoors reading. My son still has… Read more »
onewomanband
onewomanband
5 years 2 months ago
Doesn’t surprise me at all. I am a freelance writer and editor, so I stare at a computer screen all day long. When I work at home, I prefer to work next to a window rather than turn on a lamp. My vision is 20/30 (farsighted), and I’m just fine without glasses. Right now, I am working at a client’s office, in an interior room with no access to natural light. Working under fluorescent light all day is really rough on my eyes. I need to wear +1 readers (optometrist’s suggestion) just to get through the day. I go outside… Read more »
Peter
5 years 2 months ago

Very interesting article. I wonder if at 30, my nearsightedness can be even slightly abated by getting more sunlight. I’ve been getting ALOT more sunlight lately (I have trouble sleeping and am trying to get a bigger dose to see if it helps), it will be interesting if my eyesight has improved at all on my next eye test.

bbuddha
bbuddha
5 years 2 months ago

Both of my parents are myopic, my Mother has worn glasses since she was 11 or 12. Neither my sister or I wear glasses. We were outside all the time when we were young.

Shari Ciancio
Shari Ciancio
5 years 2 months ago

As children, we spent pretty much all of our time outdoors; playing indoors just wasn’t done in those days in my neighborhood (during the 50s.) Sadly, I’m myopic and have been since an early age. My brother was far-sighted. Must be in the genes.

Andrew
Andrew
5 years 2 months ago
I doubt this, too. I noticed my eyes getting bad while I was a caddy the summer before my 8th grade year. If you don’t know what being a caddy is like, it’s basically spending all day, every day during the summer outside carrying a 40lb golf bag. Plenty of good sun for 10-14 hours every day. I did it the summer before as well. The African kids have many other factors going on besides playing outside all day. In addition to caddying, I played video games at night on a small screen for a couple hours, or I watched… Read more »
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