Articles, Blog

The Nearsightedness Epidemic

January 8, 2020


When you hear about epidemics, it usually
has to do with some frightening virus like HIV or Ebola. So when scientists in the know start talking
about an epidemic of nearsightedness, it probably sounds … strange. I mean, how can something that isn’t infectious
or contagious become an epidemic? And yet: The prevalence of nearsightedness
in the US is pushing 40 to 50% among young people. And that’s nothing compared to parts of
East Asia — particularly Singapore, China, Japan, and Korea — where nearsightedness
among high-school-age children is at 80% or more. Is it because kids these days have too much
homework? Or is technology to blame? Are iPads ruining our children?! New research suggests the cause of nearsightedness
might not be peering too closely at your homework … but neither is it all up to genetics. And that might be a good thing, because there’s
a potential prevention out there that’s universal, and free. The antidote to nearsightedness might be good
old-fashioned sunlight. Nearsightedness, or myopia, is a condition
in which your eyeball is elongated. When light enters an eyeball that’s too
long, the lens focuses light in front of the retina instead of right on its surface. This creates an image that’s blurry if you’re
looking at anything farther away than your outstretched arm. Myopia is easily corrected with glasses, contacts,
or surgery. But in extreme cases, what eye doctors call high myopia, it carries a risk
of severe eye problems, like glaucoma, retinal detachment, and cataracts. Nearsightedness has always been around to
some extent. Astronomer Johannes Kepler blamed his near-sightedness
on all of the writing and calculations he did up close, and for centuries that’s been
the conventional wisdom. For a long time, peering too closely at written
material, termed near work, has been blamed as the cause of nearsightedness. Near work typically includes things like reading
and writing. Watching TV doesn’t count, because it’s far enough away, and even using
a computer isn’t as hard on your eyes. Things like smartphones and tablets are new
enough that it’s hard to say whether they should be included in the definition, but
nearsightedness has been on the rise since before they became mainstream, so they’re
probably not at fault either way. But while extensive studies have had a hard
time ruling out near work entirely, they also have a hard time establishing a firm link. So, most scientists no longer think near work
is directly responsible for nearsightedness. But In the 20th century, we learned that there’s
a certain amount of genetic influence on nearsightedness. If your parents are nearsighted, you might
be, too. But that genetic influence isn’t really
straightforward. It involves a few dozen genes, each of which only contributes a fraction
of the overall story. Plus, a study of an Inuit community in Alaska
back in 1969 showed that nearsightedness can spread way too fast for genetics to explain. At one point, only 2 out of 131 people in
that community were nearsighted — that’s one and a half percent. But the prevalence rose to nearly fifty percent
in their children and grandchildren! Genetics couldn’t possibly be responsible
for such a rapid spread. This led scientists to conclude that, while genes have some influence,
the main cause of nearsightedness must be something in our environments. And it must be something that’s dramatically
increased in recent times. While near work itself doesn’t seem to be
the culprit, there does seem to be a link between nearsightedness and education. One study, published in October 2015 by researchers
from Cardiff University in Wales, found that firstborns are more likely to be nearsighted
than later children. About 10% more likely, to be specific, which
certainly doesn’t account for the skyrocketing prevalence, but it might provide a clue. When the researchers adjusted the data to
account for how much education the participants had had, the effect diminished, which means
that it was the education of the subjects that made the difference. The scientists suggested it was a result of
so-called “parental investment.” First-time parents who make their oldest kid hit the
books might be a little more relaxed by the third one. As a result, firstborns who spent
more time studying ended up being more likely to be nearsighted. Another study, by researchers from Sun Yat-sen
University in China, compared the rates of nearsightedness in two neighboring Chinese
provinces. They looked at schoolchildren in Shaanxi,
a middle-income province, and comparatively poor Gansu province. The prevalence of myopia among kids from the
wealthy province was roughly twice that of the poor province. The researchers couldn’t
fully explain this difference, but higher math scores were associated with higher rates
of nearsightedness. So it certainly looks like education correlates
with nearsightedness, but how is this happening? And if it’s so easy to correct, why worry? Well the fact is, about 20% of people with
nearsightedness end up having high myopia. For example, more than 90% of 19-year-old
men in Seoul, South Korea have myopia. So that means nearly 20% of that population is
at risk for those serious complications we mentioned, which can lead to blindness. Having this many people at risk of serious
eye problems is a major public health concern. And eyeglasses will certainly help, so getting
glasses to kids who need them is a big priority — or, at least, should be — in these countries. But still that’s not going to address the
underlying problem. Why are so many people throughout the industrialized world nearsighted,
when our ancestors didn’t have this problem? And why is the situation especially dire in
Asia? The best guess anyone has is that it’s related
to the particular emphasis placed on education by many East Asian cultures. China has a do-or-die college entrance exam
that makes the SAT look like a walk in the park. Kids as young as 10 spend hours every
day doing homework. If education is a factor in nearsightedness,
that’s where it’s going to show up. To tease out the effect of cultural environment,
Australian researchers from the University of Sydney looked at 6 and 7 year old ethnic
Chinese children living in Sydney and Singapore. The kids’ parents had similar rates of nearsightedness–around
70%–in both study groups. But in the kids themselves, the difference
was stark. Only 3.3% of kids in the Australian group were nearsighted, compared to 29.1%
in Singapore. And the children in Sydney actually did more
near-work activities, like reading and homework, than the kids in Singapore, so that couldn’t
possibly be the cause. The only difference between the two groups
of children that could account for the difference in myopia was how much time they spent outside. The kids in Sydney spent more than 13 hours
a week outside, the kids in Singapore only 3. This seems almost hard to believe. Can sunlight
really prevent you from becoming nearsighted? Scientists and public health officials would
really like to know. But, nothing in epidemiology is ever simple. In order to figure out if natural light can
treat myopia, we need two things: Rigorous evidence that sunlight really works, and a
scientific reason–a mechanism–for it to have that effect. Fortunately, within the last few years, researchers
have made progress toward both. Experiments in animals, including chicks and
rhesus monkeys, have shown that light can protect against myopia. Researchers in Germany first tried to induce
myopia in a set of chicks using special goggles, so that all the other variables could be controlled.
Then they exposed two groups to different lighting conditions, with one group being
raised under bright light that was meant to simulate sunlight, and others under normal
laboratory lighting. Turns out, the onset of myopia was slowed
in the group raised under bright lights, by around 60%. Then the researchers focused their attention
on a substance produced by your own brain that’s known to influence proper eye development:
the neurotransmitter dopamine. In another experiment, the researchers injected
the chicks with a chemical that blocked dopamine. Without the dopamine, the protective effect
of sunlight disappeared. So it’s believed that dopamine is released
into your eyes as a result of bright light. This chemical is at least partly related to
your body’s day/night rhythm — it’s involved in the switch body undergoes from from low-light
nighttime vision to daytime vision. And it’s what lets bright, natural light signal to
your body that it’s daytime. So, researchers now think that this dopamine
cycle is needed for healthy eye development throughout childhood. If it’s disrupted, like by spending all
your time indoors in dim light, your eyeball starts to become elongated, and myopia results. This light-dopamine hypothesis is currently
the best theory for how sunlight can help your eyes develop. Best part is, sunlight is free, and it’s
an easy thing to try to see if it keeps kids from becoming nearsighted. A few studies have even looked into using
sunlight as preventive medicine. One of the biggest studies looked at primary
school children at 12 schools in Guangzhou, China. They were divided into two groups of
six schools each, with about 950 children in each bunch. The control schools didn’t change their
daily routine, but the other schools added a 40-minute outdoor activity period. Then
the researchers tracked the kids for three years. By the end of the trial, the incidence rate
of myopia in the group that spent more time outside was 30%, compared to 39.5% in the
control group. The reduction was actually less than what
the researchers expected. But still, preventing myopia in young kids is worthwhile, they say,
because the longer it progresses, the worse it gets. The most difficult thing about using sunlight
as medicine might just be convincing parents to send their kids outside more. In the Chinese study, the schools sent the
kids outside for an extra 40 minutes, but parents were also asked to send their kids
outside even more on their own time. But as far as the researchers could tell,
the parents kind of…didn’t do that. And they think more than 40 minutes is needed
to achieve the most beneficial effect. So, it seems like a victory for sunlight.
I mean, it isn’t established for sure — many studies have shown that vision quality benefits
simply from going outside, rather than bright light per se. So it could be that the effect comes from,
say, playing more sports rather than sunlight. But researchers are calling for more studies
to better establish the link, and the data so far look promising. In the meantime, fresh air and sunlight as
a clinical intervention is a pretty appealing idea. In the end, it doesn’t seem like video games
or smartphones are to blame for the nearsightedness epidemic. But neither are books and homework.
And, thankfully, it’s not a terrifying virus that’s causing the epidemic of nearsightedness. Rather, it might be an overwhelming cultural
tendency to stay indoors. So if you want to keep your kids from becoming
nearsighted, maybe sign them up for soccer. Sports: they’re good for you. Who knew? Thanks for watching this episode of SciShow,
which was brought to you by our patrons on Patreon, like Carsten Steckel and Glen Knowles!
Thank you both! If you want to help us make more content like this, just go to patreon.com/scishow.
And don’t forget to go to youtube.com/scishow and subscribe!

100 Comments

  • Reply Robert Schuster October 15, 2019 at 4:52 am

    I started thinking about this and remembered a study about the Sun and vitamin D production, that we need to be out in bright sunlight in order to produce vitamin D. I wonder if they considered giving vitamin D supplements to myopia sufferers? It's an easy enough experiment to do.

  • Reply Kie 7077 October 15, 2019 at 6:28 am

    Here's an idea: looking at things far away prevents short sightedness.

  • Reply A Remedy Project October 15, 2019 at 7:15 am

    Looking off into nature…

  • Reply 07kattho October 15, 2019 at 8:51 am

    I'm myopic, so is my brother. Neither of our parents are but our paternal grandmother is very short-sighted. We were both book worms, but I also spent a lot of time outside. I think for us it was mostly just genetics.

  • Reply Dean Crisco October 15, 2019 at 10:35 am

    Dude it's got little to do with eyesight epidemic more to do with a diet and vitamin deficiency epidemic.

  • Reply Thomas Mulloy October 15, 2019 at 11:06 am

    i was on a train from oshemambe to niseko hokkaido japan and some dude had ebola. related to all this?

  • Reply Guilherme sampaio de oliveira October 15, 2019 at 11:09 am

    Maybe what is making the difference is the lack of "far work" or looking to places far from yourself, if you never look to anywhere no more distant than a few meters (what usually doesn't happen with people who play outside) there's no wonder why this epidemic is happening.

  • Reply Adam Anti-pop October 15, 2019 at 11:15 am

    I have scar tissue over my pupil on my left eye. Took a metal belt buckle to the cornea as a child. You know why human eye's suck? Because robot visual sensors are awesome.

  • Reply rvharkless October 15, 2019 at 12:25 pm

    So what caused the increase in myopia in the Inuit population? Were the younger generations living a different lifestyle than their grandparents?

  • Reply ariel thanks October 15, 2019 at 5:27 pm

    Lmao I have nearsightedness and barely passed high school but all my four older brothers don’t have near sightedness

  • Reply Roberto Hernandez October 15, 2019 at 11:02 pm

    . …

  • Reply ace142014 October 16, 2019 at 12:03 am

    I'm just short sighted beyond 15 feet

  • Reply PaperParade October 16, 2019 at 1:19 am

    I can see it also being a bigger problem in Asia, especially China, because of the crazy air pollution.

  • Reply rj zander October 16, 2019 at 8:10 am

    Kids arent out in fields looking far away. They are inside looking ay things up close .. Derp

  • Reply Papias October 16, 2019 at 12:25 pm

    Consider looking at dietary factors, especially sugar and processed food.

  • Reply J Jamison October 16, 2019 at 2:09 pm

    Awesome video. It's very interesting to hear some facts about nearsightedness.

  • Reply Kim David October 16, 2019 at 4:22 pm

    I don't believe that. I spent lots of time outside as a kid ( born in 1954) and am still a very outdoorsy person. I wore glasses in First Grade at the age of 7. By high school I couldn't see a foot in front of my face without glasses. I was a voracious reader from the time I was 3 (yeah, I was 3 when I started to read). So there is something about school that is damaging the eye. Florescent lighting?? I know that study with the Inuit. I homeschooled my three kids and all of them finally started wearing very mild glasses in their 20's. Mild, as in it just clears things up a little so is more comfortable. So, who knows? Be interesting to find out.

  • Reply Vanessa Owens October 16, 2019 at 7:03 pm

    I was already interested in this video they didn't have to use such a cutie

  • Reply Free Bible Prophecy Book Reg6 Dot Com October 16, 2019 at 9:11 pm

    Interesting video… except for the end where he recommended sports. Jesus said in Mark 10, Mark 11, and in Luke 22 that 'he who would be greatest among you must be servant of all, and last of all.' There is no reconciling that statement and the life of Jesus Christ with what's going on in a competitive sports game. God calls us to love one another, to serve one another 24/7. Outdoor recreation would have been a better recommendation.

  • Reply CA H October 17, 2019 at 2:41 am

    Ive been working outside, in the blistering sun, since August and I am developing near-sightedness because of it. I am confident because I have had 20/20 vision all of my life and only recently my eyes have been getting blurry.

  • Reply stuligin dahooligan October 17, 2019 at 1:11 pm

    I spent more time outside than inside whn I was a kid and I'm nearsighted. Bleh.

  • Reply Gavigg75 October 17, 2019 at 5:18 pm

    Wtf are you talking about epidemic people are breeding with people with bad eyesight

  • Reply Matthew Ronson October 18, 2019 at 3:04 am

    Optometrists account for a lot of this. Look at the stats on eye specialists (i.e.opthamologist) and think of the incentive of Optometrists-notice when the Inuit started needing glasses and when Optometrists had access to their tribes.

    Note all the weasel words used here: "may be, seems to, could be, indicates, seems, etc." A long winded screed that really says little new from some hipster with ear plugs who probably still doesn't need to shave every day.

  • Reply emilydotbug October 18, 2019 at 4:53 am

    Im nearsighted…..

  • Reply Donovan Lopez October 18, 2019 at 6:38 am

    0:20 "ssstu-STRANGE"

  • Reply Zanduel October 18, 2019 at 7:17 am

    When I was younger my brothers,sister and i where always outside. I am nearsighted so idk if sun really played a role. I was the only one to need glasses I was also first born. But I have heard incubators creating pressure on developing eyes could be a cause and I was the only one born 2 months premature which is much more common in today's age with technology at keeping baby's alive. Skull development of course would effect how the eye is shaped as we grow into our bodies and i didn't need glasses for about 8 years or so I remember haveing very good eye sight for a short time.
    In my 30's I can see within 12 inches of my face and everything els is a blur.

  • Reply Fuc I dropped My Spaghetti October 18, 2019 at 7:26 am

    So the anime smart person glasses glint is a real phenomena

  • Reply Wuppler October 18, 2019 at 2:47 pm

    Too late, I'm already near sided

  • Reply Tizen October 19, 2019 at 10:18 am

    There's a fetish for nearsightedness

  • Reply Dr. M. H. October 19, 2019 at 5:04 pm

    the backstreet boyz started hosting Sci channel vdos???

  • Reply Dr. M. H. October 19, 2019 at 5:09 pm

    anxiety is the cause

  • Reply JL October 19, 2019 at 5:53 pm

    Im near sighted and have an astigmatism

    Does that count??

  • Reply Dino October 20, 2019 at 2:56 am

    Humans used to spend most of the day hunting and gathering for survival. Now we just stay home and read the directions on the back of the Hot Pocket Box.

  • Reply Nicolas Cacace October 20, 2019 at 6:40 am

    Unfortunately however curing myopia will probably cause an explosion in population growth.

  • Reply Magma_Chicken999 October 20, 2019 at 11:49 am

    I’m in Singapore and I laughed when it was mentioned that we only spend about 3 hours a week outside.

    Because it’s so true.

  • Reply werewolf435 October 20, 2019 at 1:00 pm

    Can we just get super cool robot eyes to fix this problem instead? Outside is boring and hard!

  • Reply Hark October 21, 2019 at 2:28 pm

    People with nearsightedness don't get eye fatigue from reading for long periods, right? So it may actually be an advantage if your life involves constant "near work."

  • Reply Sheldon Chad Burton October 22, 2019 at 11:14 am

    So our parents were right about not sitting too close to the TV because we could go blind

  • Reply Andreas Kvisler October 22, 2019 at 2:37 pm

    So maybe i should move, because here in Norway it’s not much sunlight

  • Reply Theresa Mayton October 23, 2019 at 10:01 am

    Interesting content, but what really stands out for me is the fact that I can more easily understand what's being said. The pace at which this lesson is given is slower than the other two individuals whom I've seen/listened to here.
    My brain can keep up.

  • Reply Chikwan Chen October 23, 2019 at 2:54 pm

    go out and play!

  • Reply Otie Brown October 24, 2019 at 12:01 pm

    Nose in page, creates negative state.
    A strong minus lens to "fix" it, only makes it worse.
    Proof?
    A minus lens always causes myopia on all normal eyes.

  • Reply sariahsue October 26, 2019 at 2:07 am

    Is there any research on treating (not just preventing) nearsightedness with sunlight? For either children or adults?

  • Reply rikiti October 26, 2019 at 8:50 am

    Seems to skip generations (somewhat) in my family. Grandfolks have terrible vision, parents have perfectly fine, I have 20/400, younger brother is nearsighted but less severe, and youngest sister has such bad vision that as a toddler doctors suspected she would have gone blind by her early teens. Definitely strange.

  • Reply D T October 27, 2019 at 8:13 pm

    Will have to put the TV outdoor now.

  • Reply pappanalab October 28, 2019 at 1:25 am

    Nah I was just born in a family with bad eyes, I'm genetically predisposed. I was born with bad eyes, seriously, I had glasses at 3 and I was a kid who was constantly outside. Almost everyone in my family has glasses and my dad has a rare-ish eye condition sooooooooo.

  • Reply - kmkitties - October 28, 2019 at 10:13 pm

    “… higher math scores are associated with higher rates of near sightedness.”
    So does that mean my 94 in math isn’t good??

  • Reply Crydack R October 29, 2019 at 1:23 pm

    Pfff I played on my iPod , and iPhone since like 7-8 and my eyesight is 20/20

  • Reply robloxgirlover 1 October 30, 2019 at 12:27 am

    yes, sunlight inproves our vision

  • Reply Michelle Parker October 30, 2019 at 12:56 pm

    What if it is genetic and environmental. We do notice a triend in families which could indicate that if your parents are that you are more likely to be but not necessarily get it. Then you have the sunlight or environment factor. Maybe its a skill of use it or lose it. Being outside generally you need to see farther distances and thus more light is reaching your eyes. This causes them to be more adapted sort to speak to seeing longer distances for say hunting prey or staying alive from preditors outside. This is not something you would need indoors or darker places, as weve also notive in other animals that spend most of their time in the dark. Anyone else understand all that lol? Not sure if I did any good explaining or if it sounds at all reasonable.

  • Reply Nelson Grant October 31, 2019 at 8:04 pm

    Well I been born like this so what was I looking at when I was 2

  • Reply Nelson Grant October 31, 2019 at 8:08 pm

    This video is not saying nothing .

  • Reply i420x Gaming November 1, 2019 at 12:59 pm

    The human race is dying due to lack of natural selection, its soo bad to think about but people with disabilitys dont just die of anymore they survive and generally pass on there genes so natural selection just cant get rid of the bad genes anymore. Dont get me rong by no means do i want natural selection to take effect disabled or not LIFE is LIFE

  • Reply Monkee Nez November 2, 2019 at 11:50 pm

    I'm the only one out of the young family members that wears glasses, even though I spent a lot of time outside as a kid more than the others. Guess I just got unlucky 😶 both my parents are nearsighted so that probably didn't help me.

  • Reply kitty cat? November 4, 2019 at 3:10 am

    So I'm very well educated?

  • Reply AmonRa November 4, 2019 at 5:40 am

    Well i have poor far sight, and i played outside all the time when i was a kid and hated studying and didn’t have too much tech

  • Reply Fossil Diver November 4, 2019 at 10:06 pm

    I thought my eyes went bad at an early age because I liked to read a lot…indoors. Doh!

  • Reply akupehsluarketatAR November 5, 2019 at 4:38 am

    I brought my kid outdoor for star gazing. I made him stare at the sun

  • Reply Ranstone November 5, 2019 at 5:56 pm

    Stop fapping. problem solved. XD
    Someone yell "Ok boomer" please.

  • Reply Spicy Artisan Hipster Salami November 6, 2019 at 7:18 am

    It’s like the eyes are elongating to teach out for the sun, lulz. Jk

    Welp, I’m off to get my kid a light that mimics sunlight to use while he’s studying

  • Reply Ferditjuh November 6, 2019 at 12:25 pm

    What about artificial light?

  • Reply Ross Meldrum November 8, 2019 at 1:41 am

    I spent my entire summer outside as a kid every day, all day long, every year for more than 2 decades. I still ended up extremely myopic.

  • Reply shng sam November 8, 2019 at 1:04 pm

    nope.. sunlight is not the answer,
    we near to Singapore have a lots of sunlight

    the cause of high number of nearsightedness is so simple but no one want to admit : Business

    our eyes is not perfect, and might be blur sometimes
    than children tell this to their parents, and their parents take them to check the eyes
    even though it is very mild, spectacles is prescribed

    once human wear spec, the eyes change shape and will require more thicker spectacles constantly. I am one victim and i can say that my eyes and those around me who wear spec, the eyes shape is different.

  • Reply Michael Oakes November 8, 2019 at 6:59 pm

    "[Nearsightedness] creates an image that's blurry if you're looking at anything farther away than your outstretched arm."

    HA! I frikkin' WISH I could see that far. Without my glasses, my maximum range of clear vision is something like 2-3 inches from my nose. Reading? Forget about it. My maximum range for text on books or screens is about an inch from my nose.

    The last time I went to the optometrist, I asked him where I fell on the 20/20 scale. Note my utter lack of surprise when he told me that without my glasses, my vision was a bit worse than 20/8000. I didn't even know the number WENT that high!

    And even WITH my glasses, my vision isn't perfect: While wearing my glasses, my vision is somewhere between 20/60 and 20/80. If I wanted anything better, I'm looking at $100 out of pocket for glass lenses, since my insurance only covers plastic lenses, and I'm at the upper limit of what plastic lenses can handle…

  • Reply dreamcadet November 9, 2019 at 4:56 pm

    I have the opposite thing. farsighted gang rise up

  • Reply 49jubilee November 11, 2019 at 7:53 pm

    Either nearsightedness, or need reading glasses

  • Reply Aiden Allred November 14, 2019 at 1:07 am

    Dude people think they got it bad I got all sorts of crap in going in my eyes

  • Reply Skyrilla November 14, 2019 at 1:45 pm

    What's with your restless hands?

  • Reply Matt Huffman November 15, 2019 at 10:51 pm

    Do sunglasses have any effect on the benefits of the sunlight exposure?

  • Reply JASMEET SINGH November 16, 2019 at 8:41 am

    Liar liar pants on fire. No one will blame the smart phones which are the biggest reason for the epidemic now.

  • Reply Fire Feather November 16, 2019 at 3:23 pm

    lol so im half nearsighted so does that mean i only study enough to be a C student? XD

  • Reply Eli_Tomac_Fan 668 November 16, 2019 at 7:15 pm

    I go outside regularly and I still have glasses :/

  • Reply First Last November 17, 2019 at 9:56 am

    born with it

  • Reply jeaniebird November 18, 2019 at 12:29 pm

    It's from not being outside and looking far. When we're inside, our eyeballs don't get that type of "exercise". That's why people that spend more time outside, such as fisherman, have less issues with nearsightedness.

  • Reply Casey Loomis November 19, 2019 at 5:28 pm

    It looks like stress is the one factor common it the rise in nearsightedness. Going outside is less stressful then studying and stressed can be passed from parent to child by epigenetic means.

  • Reply 스테파니 Stephanie 조셉 November 22, 2019 at 12:38 am

    My far sight is getting blurry so I'll go outside tomorrow and even more now that I know this information.

  • Reply oriana garrido November 22, 2019 at 1:56 pm

    Boi oh boi, nerd stereotype is real.

  • Reply Anon Mason November 22, 2019 at 10:32 pm

    Sports. They're good for you.
    Except the video on how sports cause brain damage and life long injury to kids.

  • Reply Rmdhn November 23, 2019 at 8:28 am

    Not enough sun? Near sighted
    Stare at the sun? Blind

  • Reply Shane Morris November 30, 2019 at 5:00 am

    So if a far sighted person goes outside more it'll even out, fixing it? Haha

  • Reply spider doom December 1, 2019 at 6:59 pm

    I agree with the part about getting outdoors in the bright light. I'd say as much as possible. If you're already nearsighted, wearing a weaker prescription that corrects you to 20/30 or 20/40 is all you need. Not going to get into the science about it on here, but that's how i improved my eyesight back to perfect. It takes time and dedication, but it is possible.

  • Reply Rick Corthals December 4, 2019 at 6:44 am

    Tried to cure my nearsightedness by staring at the sun for 2 hours. Now I can't see anything 😔

  • Reply Winona Daphne December 6, 2019 at 3:00 am

    me: learned today that dopamine influences proper eye development
    also me: was depressed and cried myself to sleep every night at grade 4

    ah. makes sense. that's also about the time i started having vision problems but didn't tell my parents until a full year later because i knew they would beat me.

  • Reply Tempo December 8, 2019 at 4:44 am

    My eye sight was perfect my whole life, but a few months after I started reading novels a lot I noticed that my eye sight was getting worse.

  • Reply eriathdien December 8, 2019 at 2:11 pm

    Kids, just remember to put on sunscreen

  • Reply Adam Roodog December 9, 2019 at 8:41 am

    My 2 cents. Could it be that outside your eye is focusing at a greater distance?

  • Reply Hailen Ace December 9, 2019 at 7:16 pm

    "sunlight is free"
    People in scandavia:

  • Reply Brendan December 10, 2019 at 4:45 am

    Funny how I find out that I'm nearsighted then this pops up in my recommended

  • Reply Otie Brown December 10, 2019 at 11:21 pm

    Prevention is free.

  • Reply FUMIF HONDURAS December 11, 2019 at 1:03 am

    MOM I¨LL NEVER GO TO SCHOOL AGAIN, IT MAKES ME SICK

  • Reply S C December 13, 2019 at 7:07 am

    oh wow

  • Reply IndoHati Carol December 14, 2019 at 10:43 pm

    I'm 48 years old…For a while now ,I never wore glasses or thought I needed them.2 weeks ago I finally went to get an eye exam and found out I'm nearsighted.😓🤦So amazing how clearly I see now when I'm driving.I am indoors alot ,but when I'm outside I never wore Sunglasses ..love the sunlight .I still need eyeglasses.🤓🤷Idk

  • Reply Geoffrey Harris December 14, 2019 at 10:59 pm

    People should avoid eletronics and too much reading.

  • Reply Geoffrey Harris December 15, 2019 at 4:35 am

    Get plenty of time outside in natural light. You need lots of dopamine from bright natural light.

  • Reply Elizabeth McGlothlin December 15, 2019 at 11:01 pm

    Not enough predators chomping up slow-running, near-sighted children anymore. Farsightedness used to be a survival bonus.

  • Reply Torment December 16, 2019 at 10:30 pm

    I think the sunlight argument stands. As artificial lights are what define our lives nowadays for the most part. If it is not genetics, then it is a combination of nearsight work and whereabouts of our eyes, where we tend to look down when walking cause there s nothing particular to look at in our suburbs so we just pay attention to the near sights, combined with the fact that something like 80 percent of our day is spent indoors where there is poor natural light, making our eyes more stressed to focus on things. For instance i have myopia, and whenever there is a very bright sunny day, i just see everything almost crystal clear to the point i even forget my condition. Whereas when it s dark i barely can see past 2 meters clearly. So yes, i definetly think sunlight plays a big role, dont forget that we evolved thanks to the sun, we are kinda related to it, it is our mother and our power source, but of course we keep evolving making glasses and adapting to our condition.

  • Reply crazycatlady39 December 17, 2019 at 12:38 am

    6:22 That makes me think of SAD or Seasonal Affective Disorder. It's really a Depressive disorder, but it uses the day/night cycle triggered by light amounts. There's actually two versions-the one most people think of when they talk about SAD where you struggle during the winter due to low light levels particularly in Northern climates; but there is  also an 'opposite' version where you struggle during the summer due, why I'm not sure.

  • Reply Dave S December 17, 2019 at 4:39 pm

    anything new on this topic in the past several years?

  • Reply TheFourthWinchester December 22, 2019 at 6:34 am

    Hinduism's ancient Surya Namaskara in the morning light says hello.

  • Reply TreeMobile. December 26, 2019 at 4:35 am

    Theory: It might be because of bright light having to make our brains focus the eye harder, and once you run and play, its going to be harder to focus the eyes to a target, with the blinding sunlight in the way.

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