Outdoor time is good for kids' eyesight

I watched a Japanese doc about this phenomena a couple years ago. Japan's genetics haven't changed in recent decades but now basically everyone leaving highschool needs glasses. So they strapped lasers to kids to measure the distance in front of their face, to track their focus distance throughout the day. The results and outcome were telling, suggesting a conflict of cultural standards regarding eyesight.

The worst, closest, time was while at school. The kids were learning writing, Japanese characters. They were sitting at desks, their heads looking straight down onto paper as they learned to create tiny perfect characters. But at the doctor, the kids were given eyeglasses to correct their vision to the 20/20 western standard which itself is largely based on operating vehicles or seeing blackboards in giant lecture halls. So kids with glasses optimized for distance were forcing their eyeballs out of shape to focus on schoolwork literally inches from their face. The finding was that perhaps Japanese eye doctors should prescribe glasses based on what kids actually need (close focus) rather than pretending they all are going to be driving cars and flying planes.

This interestingly opens up another example for exploration of nature vs nurture.

I always thought my good eyesight was from genetics from my father's side--but maybe it was the relatively free-range upbringing that he both experienced--and also paid forward to me--that might have been the deciding factor.

I'm truly scared of the future we're building, most kids I meet already have permanently damaged spine from looking at their phones/tablet 24/7 (quasimodo style). Their attention span if absolutely fucked, a lot (most) of them are already fat, now apparently they're losing eye sight. And on top of that they apparently suck at computers.

The scale and pace of the transformation is insane

Who would have thought it's good for the health of children and indeed all humans to be outside and involved with nature

My generation's grade schools: 20 min playground time after morning bus drop off, 30 min after eating, a 15 min recess and PE time. In the evening, we had 30 min of homework total.

My kids grade schools: 15 min playground time after eating. The 5-6 classes gave 30-60min of homework, each. So it was home, eat, homework, cubscouts/etc, eat, homework, bathe, bed.

It was almost just as well. There was ~nowhere for them to go past the yard (and 92°/90% humidity+heavy gnats).

In the future, we will live in a garden city and commune with nature and look back on this error of fat people living in skyscrapers as a dark age.

Outdoor time is good for eyesight... But is bad for sunburn. Bad for learning math. Bad for getting wet in the rain and cold in the snow. Bad for breathing in polluted city air.

There doesn't seem to be enough data to truly say what the ideal amount of time outdoors is.