As one meta-analysis put it:
It’s estimated that an increase of one hour per day of outdoor time could reduce the occurrence of myopia in children by 45%.
Make sure your kids spend time outside, folks!
I’m pretty sure short-sightedness is more a result of patience and critical thinking, but outdoors might help near-sightedness.
YSK: The word is ‘spent’ not ‘spend’.
Yeah that was a typo. Edited the title to fix it, should be correct now
Sometimes I wonder if people see numbers like 45% and think “OMG, 45% chance!” instead of “small number * 1.45 = another small number.”
Considering that a fairly large percentage of children develop myopia (as high as 80-90% in some countries) a 45% reduction would be fairly significant, no? Or am I missing something
where are you getting these numbers… from what I can see, the global average was 23% in 2000 and 34% today.
The 80-90% claim seems to be repeated in various areas on the internet, including by the American Academy of Ophthalmology, which I assume to be reputable:
Over recent decades, the prevalence of myopia has skyrocketed, particularly in Asia. In countries like China, Japan, Singapore, South Korea, and Japan, up to 80-90% of teenagers and young adults are now myopic.
Of course these local averages are still consistent with a lower global average
One hour of outdoor time per day is not a modest increase
For some people it is
well, i can concur. my eyes have trouble adjusting to looking into the distance when i have spent hours in front of the screen. they adapt after a few minutes to hours though.
Good try child sports teams. I ain’t touching that grass unless you make me.
“Also, while various theories such as increased light exposure, release of dopamine from retina, increased depth of field have been suggested to explain the protective effect of outdoor time, the mechanism remains to be elucidated”
Correlation is not causation.
That depends entirely on how the correlation is determined. For example randomized control trials can establish causal inference.
You can establish causation even if you don’t know what the mechanism is. I don’t know to what extent causation has been established here though, I’m not familiar enough with the research. But at minimum the intuitive idea that there is a noncausative correlation because kids with bad eyesight choose to stay inside more does not seem to stand, since this phenomenon can exist at a population level (so countries where schools start younger - and kids go outside less - have significantly higher rates of myopia).
I don’t know to what extent causation has been established here though
I am familiar with the research. We don’t know the reason for nearsightedness. There is no known proven causation. It is likely there are different causes for it.
Being from a sunny country lowers the chance of it (so you’re less likely to be nearsighted if you’re from Spain compared to Norway), even when controlled for hours spent outdoors.
There are studies that just look at outdoor time. I don’t think we know the specific mechanism but we know enough to have recommendations.
My eyes have been terrible since 1st grade. My prescription got as high as 9s.
Then I got cataract surgery on one eye, and I can see nearly perfectly without glasses for the first time in my life. This summer, I’m getting the other one done, and I won’t have to wear glasses anymore, for the first time in my life.
Anyway, the point is: As I was talking to the eye surgeon, and mentioned my bad eyesight, he told me why: I have the eyeballs of a man who is 7’2" tall, jammed into my 5’11" skull. Apparently, I have enormous eyes, which nobody has ever mentioned to me, other than one brief girlfriend who used to comment on my gigantic green eyes.
If I had to get something big from a 7’2" inch man, why did it have to be eyeballs?
Wow I didn’t realize that cataract surgery can improve your vision that dramatically. I thought cataracts surgery was something typically reserved for seniors to prevent foggy vision
They fully replace the eyes’ lenses, so they can give you lenses that correct your vision. It’s just not a great idea to do surgery for something that can still be corrected with glasses.
It’s just not a great idea to do surgery for something that can still be corrected with glasses.
Well I generally agree, there are people who elect to get laser eye surgery. Is this procedure generally considered more risky than laser eye surgery?
They have to destroy your natural lens to make room for the replacement so it’s a bit riskier than laser correction.
Makes sense
Well, yeah, I’m old, and there were cataracts in both eyes, but one went bad real fast, over the course of a few months. The doc told me that it’s kinda rare, but it happens. What was weird is that it only happened in one eye, so at least I could see with my one good eye, but if it happened to that eye too, before I could get the surgery, I’d be screwed. I literally wouldn’t be able to see well enough to drive, read, anything.
So the new lens corrected for any bad eyesight, more or less. I haven’t had it tested now that it’s fully healed, but it probably isn’t perfect 20/20, but it’s close. I have a contact in my other eye, which is still at a 9, so very bad. It also has a light cataract.
Now I can see the difference between the two eyes. In my new eye, colors are brighter and sharper. In my other, cataract eye, colors are slightly, but noticeably muted. I probably wouldn’t even have noticed it, if I didn’t have the new eye for comparison.
I’ve also noticed that late at night, when I’m tired but still watching TV, I get double vision. I have to consciously focus. The doc warned me that having a good eye, and a contact lens eye would mess with my vision, and I think this is what he was talking about.
The doc said that now that I’ve had one done, the insurance will probably spring for the second one, even if it isn’t necessary yet. That means I’ll have nearly perfect vision, and maybe need reading glasses. I use reading glasses with my new eye, but if I don’t have them, it isn’t a big deal, I see well enough for most stuff.
Sorry to yak so much about it, but It’s kind of exciting, being able to see so well for the first time, as an old person, and I don’t really have anyone else to tell it to that would care.
Amazing! Congratulations on your new eyesight!
That’s fascinating. Is it typical for cataract surgery to cause near 20-20 vision or is this something that just happened to you because you have a unique eye shape?
No, the doc said this would get pretty close. I don’t think they can ever predict exactly where your vision is going to land, but he knew it would be close enough for reading glasses, which I never go anywhere without anyway, even with contacts. They are replacing your lens, so why replace with just a clear lens that is the same as your poor vision, that has to be corrected with supplemental lenses, when you can just replace the lens with a correct one, and fix the entire problem at once.
Of course, an immoral eye doctor might want to fix the blurry cataract, but keep your eyesight poor so they can continue to sell you glasses and contacts.
So I was expecting an improvement, and it certainly got darn close. Closer than I’ve experienced for most of my life.
BTW, it also wasn’t really painful at all. It was uncomfortable the first day, but not itchy or painful, much less so the next day, and was pretty normal in 48 hours. I took a Tylenol/Advil combo, and drops they gave me.
They can’t predict with 100% accuracy, because vision isn’t a completely objective matter as it also takes into account your brain’s interpretation of the image, but they can get pretty close. The exams you took probably measured your eye’s axial length, your cornea’s keratometry, diameter and other measurements.
Your ophthalmologist then selects the formula that best suits your eye (there’s different mathematical models for different cases of myopia, hypermetropia and how extreme they are) and then the lens’ power is calculated according to the measurements that were taken. Usually the device that takes your exam already does like 80% of the job (in the mathematical side of things), but your doctor uses their criteria to define the final IOL and from where it’ll be inserted during surgery*.
It’s pretty cool to take that exam. In my country I used to take it for patients that were going into eye surgery.
* It usually means a little bit more math
Is this procedure ever performed on someone with healthy cataracts to improve their eyesight?
I’m not sure if there’s something as healthy cataracts. Every case of cataracts has to be eventually treated by removal of your eye’s lens and then replace it with an intraocular lens (IOL).
If you meant if its ever done on a healthy lens, I’m not really sure. There’s a technique for installing an IOL on top of a previously installed IOL that’s called piggyback IOL, but on a healthy lens without cataracts seems uncommon.
Lensectomy and IOL placement can occur when the patient has a healthy lens in some cases though. When they’re going through other issues such as proliferative diabetic retinopathy, fibrovascular proliferation can occur in the vitreous humor, which would require removing it (the procedure is called vitrectomy). In some of those cases, the replacement of the vitreous humor accelerates cataracts development, which means that the lens will have to be replaced with an IOL.That’s what comes to mind from my experience doing those exams many years ago, I could be wrong.
If we take your eyeballs and take my teeth (“You have the roots of a 6’5” man" inside my 5’4" female body) we have the start of a good build!
Which of us is Doctor Frankenstein though?
You were made for anime, not office work
I was outside a lot and still got myopia :3
Congrats on the luck
Same for me, I spent most of my free time as a child playing outside. I grew up in California, weather wasn’t a concern, I was outside year-'round. I got my first pair of glasses at age 21. I suspect it’s far more genetic than environmental.
It’s both. You can just look at the statistics, the number of people with myopia has gone up over the last few decades. If it was just genetics those numbers would have been stable.
Well, unless nearsighted people were outcompeting people with 20:20 vision, for some reason.
N=1
Then you were likely genetically predetermined to be at least a little myopic, but if you spent less time outside during your developmental phases you would likely be even more nearsighted than you are now.
N=1
LMFAO
My mom blamed us (me and my older brother) for “sitting too close to the TV”
She kept us mostly locked indoors in an apartment (besides going to school) from the beginning of my memory up till 8 years old.
Then we moved to the US and from 8 to 12 I was in school from morning (like 7 AM maybe? forgot the exact time) till like 6PM cuz she signed me up afterschool programs cuz she wanted to use it as free babysitting essentially so she can work longer…
And we cant go outside alone without adults.
In China it was “a lot of kidnappers on the street thay will traffic you and sell your organs”
In the US it was “if you go outside without an adult, CPS will take you away and you can’t see mama again” (idk why mom spoke in 3rd person sometimes lol)
Yay! so… from birth to 12 I was indoors, either in school or at home, most of the time…
outdoor time was rare and only when parents have a day off or like the 15 minutes of recess in school…
that’s basically our outside time…
In China we had maternal grandma that sometimes took us outside…
In the US, it was just mom, dad, older brother, and me (cuz grandma can’t come yet, no visa yet)… So we had even less outside time… like parenrs had to work all the time…
But of course its always “too much screens!” to be blamed lmao
From 8 to 12 was when my nearsightedness really developed a lot.
I didn’t understand why I had nearsigntedness at the time, but now looking back and analyzing my life, now it’s so obvious why lol…
My older brother has like -9.00 or -10.00 in the nearsightedness thing. Its funny my parents called it like 900 or 1000 “degrees”… like it sounds so much scarier when they drop the decimal point and literally say: “you’re about to have ONE THOUSAND DEGREES IN NEARSIGHTEDNESS! You’re gonna GO BLIND!”
did not seem to help me. I guess I got the bad side of the coin flip.
Is this really causation though? Could it not just be that kids that spend less time looking at screens are less likely to be short-sighted AND more likely to spend time outside?
If this is just a correlation this would have to be a correlation at the population level. Countries where kids start school later on (e.g. 7 years old) have significantly lower rates of myopia than countries that start school early on in a child’s development (e.g. 3 years old). It’s still possible that this is a correlation, but the correlation would have to be capturing something deeper than just an individual kids screen time. Granted, this correlation would still need to account for differences between individual kids, but it would also need to account for differences between kids at a population level. It’s hard to see what could be causing this correlation though. So maybe there’s something there we’re just not seeing, but at a certain point though the idea that there is a causal relationship starts to seem like the most plausible explanation for explaining this data
It wasn’t mentioned in this article, but I remember reading somewhere that it might be because exposure to sunlight affects vitamin D production, which affects the length/shape of our eyeballs as we’re growing up.
Another idea is that when you’re outside, you spend more time focusing on objects further away, which helps develop those eye muscles
A third idea is that sunlight is much, much brighter than most indoor artificial light, and the lack of this very bright light causes some sort of problem for the developing eye. Maybe the brightness of the sun is a sort of “calibration” method for the eye and when it doesn’t get that really bright sunlight, the development of the eye goes out of whack.
So is it vitamin D, or far-away views or bright sunlight? I’ve heard all these theories before but I’m not sure which is it. Does the meta analysis say anything about which effect is most likely the cause? I mean could we “fix” this by going outside to view things far away, or should we just take vitamin D supplements, or should we have much brighter indoor lighting? I’d love to know.
A third idea is that sunlight is much, much brighter than most indoor artificial light
Would this mean it’s a bad idea to give kids sunglasses?
Does the meta analysis say anything about which effect is most likely the cause?
Not that I saw though I admit I didn’t read the whole thing
Would this mean it’s a bad idea to give kids sunglasses?
Well if that is actually the causing effect, yes. I checked the paper and they do actually mention light brightness as a potential cause, as well as the other things but they have nothing on what actually causes the problem for real.
But I mean, clearly we aren’t naturally meant to need sunglasses so in a way I’d say yea, don’t give your kids sunglasses.
I’ve seen that too, with some emphasis put on viewing the horizon… though where I grew up it’s very unlikely to see anything close to horizon-distance without being at a beach (mostly because trees… better than indoors sure but not much non-treetop distance to look at unless you’re looking across a field/farmland, or maybe a radio/water tower or something).
though where I grew up it’s very unlikely to see anything close to horizon-distance without being at a beach
It would be interesting to see if people who live im these sorts of areas have higher rates of myopia. I’m not aware of any data that’s been collected on this though
if you want sad but unfortunate proof, read about the case of genie. https://en.wikipedia.org/wiki/Genie_(feral_child)?wprov=sfla1
the relevant bit here is that when she was taken out of the room she was kept in till age 13, her eyes were literally unable to focus on anything more than 10 feet away (as that was the size of the room she was kept in). imo that shows that being outside where objects tend to be farther away at a young age helps train your eyes to do so in the future.
If you get this type of short sight vision, you can train your eyes to get the vision back as this is caused by the eyes strength.
But if you have the type that has to do with your eye shape going outside will do nothing, and you can exercise it away
Yes, I spent 6 months in ICU in 2014, I had a lot of eye issues while I was there not related to my reason for my stay (bilateral lung transplant) but as side effects of procedures and meds but I also basically lost my depth perception unless it was directly in front of me. Living in a 10x10 room for half a year with no far away distances to observe made my eyes weak, it took about six months after I got home to get my full depth prescription back. Indoors just makes your eyes weak, mine is an extreme example, but it doesn’t permanently ruin them.
You need to read better. It says it reduces occurrence of myopia in a population not that it cures myopia when an individual gets it.
Sure if you have very mild short term myopia caused by eye straining you can get vision back by training your eye. But with kids it’s about how the eye develops when it’s still growing. When kids eyes grow too fast they grow less spherical and that is what causes myopia and that is the kind that you can never cure. Going outside means kids are getting more sunlight in their eye which will slow down the growth and thus their eyes will grow more spherical which means they don’t develop myopia. Playing outside won’t cure myopia but it will reduce the chance of developing it in children.
Ysk 0*infinity = 0
If you spend no time doing anything that you ought to do (exercise, go outside, eat healthy) the immediately observable effects from any amount of sustained practice is measurable.
I’m farsighted, so I can only conclude that I spent too much time outdoors as a kid. See Mom!?
