So when you're looking at close screens or books for most of your day, the eye makes that be the "at rest" state, but now distant objects are blurry. Now if you insist on having distant objects not blurry (by wearing glasses _all the time_), it's the same situation again and the eye will "adapt" even more, and you'ell get more power glasses, and so on...
If that's true, then people with myopia shouldn't wear their glasses _all the time_, particularly when staring at close objects (screens and books). I have myopia and that explanation fits my experience. Most of the time I'm looking at a screen not wearing my glasses, and the screen is exactly at the right distance for me to not to have focus, so my eye is "at rest" for most of the day.
It sounds weird that a lot of eyes are dysfunctional. Maybe we don't understand how eyes find a trade-off that best suits your average focal distance. It also gives a rational as to why myopia went from a few 1% to 50% of the population in some countries. People started staring at close objects.
I don't know if it's actually true, but it makes a lot of sense to me.
Your idea about allowing the eye to "rest" is not new and it has been the subject of several large scale clinical trials such as the COMET study linked below. In short, under correcting myopia does help to slow down progression. However, the benefit is too small to justify not fully correcting vision which will result in a better quality of life.
After WW2, Canadian Inuits started to send their children to school for the first time in history and myopia became endemic from that generation onwards.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1956268/
And to put the source in context:
- This was before the age of computers and smartphones so screen time was much less of a factor.
- Inuits traditionally spend a disproportionate time indoors due to the climate.
- The schooling was likely shorter and less stressful than those found in places like Japan and Korea, yet the effects are just as apparent.
Similar rises in myopia rate was observed when daily schooling was introduced to many other places, but few occur on the same scale. Thus it is possible that Asians and Inuits are genetically predisposed to myopia and it took until the modern age for this to become a problem.
My optometrist specifically prescribes me lenses/contacts that are slightly worse than optimal (i.e. -2.25 instead of -2.5) based on the fact that I stare at a computer screen the entire day. IIRC her explanation was along these lines, and I've had no degradation in eyesight in nearly a decade since. (I am not an optometrist, for god's sake find your own)
There's less sunlight in the North during the winter, sure, but still several orders of magnitude more than inside (also, more UV etc.).
But this hypothesis also has problems. For example, less refined carbohydrates apparently do not lead to this. Also it does not explain how adding more meat to refined carbohydrates affects the mechanism.
There was also Australian paper I cant find now, showing that prevalence of myopia in Asians in Australia is much lower due to school systen encouraging more free time and play outdoors. (not explainable by genetic factors)
Children must play outside in the sun or they become myopic.
[1] https://pubmed.ncbi.nlm.nih.gov/29371008/