Light levels outdoors will generally be much higher. As a result, the pupillary diameter will be smaller (a higher f stop in camera terms) and the depth of field will be much deeper and allow higher spatial frequency “reading” with minimal physiological accommodation.
This study wasn't conclusive: https://iovs.arvojournals.org/article.aspx?articleid=2360831
"Overall, the results suggest that eye exercises have limited to no efficacy in preventing or controlling myopia progression. Until robust evidence supports their efficacy, available evidence suggests retiring the eye-exercise policy."
I don't know if going outside more often will reverse it.
Astigmatism, on the other hand, may be hereditary.
I don't know about you, but in my case that would have been "just push". RCT1+2 was a lot more fun and even if I would play with the (often mean) village kids, they too were more into video games than ball games, albeit more something like Postal (rated for mature audiences, like ten years older than we were). There was some voluntary playing outside as well as inverse curfews imposed to make sure we don't only game and watch Pokémon inside at some age, but this notion of "just let them do what they enjoy" is so contradictory to my personal experience
In the US, the complicating factor is that parents get in trouble for letting kids play unsupervised outside. Both custom and legislation discourages this kind of parenting. There is an advocacy group in the US trying to lobby for legislative protections for parents, so “just let them play outside” means something a bit different.
I did, most of my young life, and I'm still myopic. This can't be so easy
Did you play an hour a day during solar noon?
(It would actually be cool to see if myopia rates change along towns near a time zone border -> kids getting out of school during the brighter time of the day)
This isn’t something one has to spend a lot of time optimizing within certain latitudes, since there are benefits for kids being outdoors beyond halting progression of myopia. Although, if you think this can reverse myopia, it is worth biohacking.
If I recall, the article I read on this was posted on HN.
The second thing I would ask is if you have astigmatism or myopia. They are not the same thing.
The third thing is that the Taiwanese protocol included an early childhood intervention for a portion of the population. They have a test and an additional treatment. I don’t remember the details. If you have myopia instead of astigmatism, you might be one of those kids.
Lastly, there are still some kids who develop myopia anyways in Taiwan after establishing this program.
Here is an excellent paper in Nature Genetics:
https://www.nature.com/articles/s41588-020-0599-0
But you are right that environmental factors are also critical. Most types of myopia are modulated by gene-by-environmental interactions.
Lots of near-work is the number 1 culprit. But susceptibility to near work is a function of your genome.
I grew up rurally and can guarantee I spent more time outside than most. It was almost impossible to get me back inside. I’d leave early AM and go explore our until dark day after day, month after month year after year. Yet I still ended up with myopia (that started very young.)
Of course, I probably just got unlucky. Across a population it’s probably good advice, but it’s not a magic bullet and it’s not a guaranteed answer.
That being said if I was inside, I as almost guaranteed to have my nose in a book. Wonder if that had any impact despite my consistent exposure to outside.
Body height is largely hereditary if you can avoid malnutrition. But improved nutrition has led to an increase in average height over time.
It's not improbable that spending ten hours a day indoors to study could have an effect on myopia in children, even if the variation among children who all study for approximately the same duration appears to be explainable by hereditary factors.
To be clear, good environment increases the phenotypical expression of genotype. A malnourished population will have lower height variance than a well-fed one ceteris paribus.
But I honestly do not know the answer. Perhaps I should ask an LLM. But this might be a goid place to start instead.
Similar studies have been conducted in China for multiple times, no clinically significant results were ever found. It probably doesn't help anybody, other than encouraging a short while of not using your eyes.
The guy who first invented the exercise basically just made it up from thin air, trying to fix his own myopia, which was a reasonable effort that didn't work out. But for some reason, it caught on in schools nevertheless.
The above claim strays far from the way of logic. Follow that pattern of thinking, and you'll never run out of things to try.