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!
Near-sightedness
https://en.wikipedia.org/wiki/Myopia says that both terms exist in English? Not a native speaker; I think I have seen “nearsightedness” more often in English but my first language’s term for it translates to “shortsightedness”. 🤷♂️
I was outside a ton when I was younger and I still have myopia. These things happen.
You might have had a higher degree of myopia if you hadn’t spent all that time outdoors.
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?
You were made for anime, not office work
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?
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
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!
You prefer big feet?
One hour of outdoor time per day is not a modest increase
For some people it is
“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.
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.
This is very interesting
I’m pretty sure short-sightedness is more a result of patience and critical thinking, but outdoors might help near-sightedness.
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.
Hold up now. I grew up in the 80s when we spent the whole day outside, and I wore thick ass lenses all through grade school.
“Reduces chances” does not mean “prevents”
irrelevant because the term used here was “odds”, not chances
smfh
Uh OK same reply
damn people on Lemmy don’t like sarcasm huh
Oh good one
Yeah, I always had terrible eyesight, and I probably spent more time outside than inside. There was nothing fun happening in the house. ALL the fun was outside.
You should have “spend” the day outdoors not “spent”.
No. Spent is the past tense of spend.
They edited the title.
Ohhh, I see. I thought you were just a really bad grammar Nazi.
How do some people despite being wrong are happy to correct others? And they have up votes? Wtf…
My comment only makes sense with the original misspelled title of the post.
I see, my apologies then
We spent so much time outside we developed near sightedness instead
YSK: The word is ‘spent’ not ‘spend’.
Yeah that was a typo. Edited the title to fix it, should be correct now
I was outside a lot and still got myopia :3
N=1
Congrats on the luck
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.
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
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
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.
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.
Yes exactly. But for people with near vision from eye shape there is nothing you can do exercise wise to restore vision.
I’m farsighted, so I can only conclude that I spent too much time outdoors as a kid. See Mom!?
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?
There have been RCTs conducted for this. For example
Myopia Prevention and Outdoor Light Intensity in a School-Based Cluster Randomized Trial
Pei-Chang Wu et al. Ophthalmology. 2018 Aug.
In this study, schools were selected and promoted either outdoor or indoor recess
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.
did not seem to help me. I guess I got the bad side of the coin flip.
