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!

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
We spent so much time outside we developed near sightedness instead
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.
I spent 90% of my early childhood outdoors. Didn’t work.
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 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 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
Nah, there were early studies on this pre-internet, which also means pre-smart devices.
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
but my electronic image generator makes bam bam noise, must spend more money for more RAM
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!”
lol “Degrees” would just be the literal translation from Chinese to English for how they talk about nearsightedness in Asia, nothing about scariness lol
Does it work for adults too?
It probably helps against making it worse. My father always told about the 30-30-30 rule.
Every 30 minutes
For 30 seconds
Looking at least 30 Meters into the distance
No. Interestingly once myopia does start developing this doesn’t seem to slow the progression. It seems to be good for prevention and that’s it
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
Good try child sports teams. I ain’t touching that grass unless you make me.
I admit that I barely skimmed the article so I don’t know if/how they controlled for this
But this also kind of feels to me like something that could go the other way- myopic kids are less likely to go outside
Get hit in the head by a baseball you didn’t see coming or trip over a rock you didn’t see a handful of times and you might decide that the “outdoors” thing isn’t really for you.
Or of course a mix of both factors, kids who are already predisposed to short-sightedness go outside less, so the other factors at play make their eyes even worse and so they go outside even less and…
But this also kind of feels to me like something that could go the other way- myopic kids are less likely to go outside
It’s not just individual kids they are measuring, but entire populations of children and at what age they start school. The younger kids are when they start school, the more likely they are to be myopic, and this contributes to significant differences in the prevalence in myopia across countries (Edit: I should have stated this explicitly, but this is because more time in school means less time outside, generally speaking)
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.









