I believe myopia is primarily caused by less use of the eyes to focus on a variety of distances and scenes. We mostly are indoors looking at books and now screens -> myopia goes way up. I also believe it can be reversed by using the eyes differently and this happened for me.
I had myopia from when I was a teenager. I didn't realize it till I was 21 and tried glasses and could suddenly see what I didn't know was possible to see. I then wore glasses from 21 to 27. Quit wearing glasses at 27 and left the office and computer to be mostly full time in the woods. Two years later my myopia had mostly reversed and I could see crisp detail at long distances without glasses for the first time. Six years now since I noticed the reversal and I still can see clearly at long distances. I love it.
Happy for your anecdote. How much was your prescription?
Additional sources? Quick literature search doesn't confirm this: t.ly/k4I_1
Original article: "Human accommodative visuomotor function is driven by contrast through ON and OFF pathways and is enhanced in myopia" - https://www.cell.com/cell-reports/fulltext/S2211-1247(26)000...
Summary. "The human eyes are continuously adjusting refractive power, vergence angle, and pupil diameter when exploring the visual environment. Adjustment errors in these visuomotor functions reduce the stimulus contrast driving ON and OFF retinal pathways, and ON retinal pathways become weaker, slower, and less sensitive in refractive disorders such as myopia. Here, we demonstrate that, in addition to these sensory deficits, myopes also have deficits in visuomotor functions driven by ON and OFF pathways during lens accommodation. We show that humans with myopia have excessive accommodative eye vergence with reduced ON pathway dominance and excessive accommodative pupil constriction. The excessive accommodative pupil constriction that we demonstrate could potentially weaken ON pathway responses and cause ON pathway deficits. This mechanism could explain why myopia increases with activities that maximize accommodative pupil constriction, such as near work, and decreases with activities/treatments that reduce it, such as outdoor activity, atropine, positive defocus, and low contrast."
"Myopia has reached near-epidemic levels worldwide, yet we still don't fully understand why," said Jose-Manuel Alonso, MD, Ph.D., SUNY Distinguished Professor and senior author of the study."
It's because you focus on nearer things much more time than things which are far away. One does not need a PhD and the whole kitchen sink to notice that.
Why does focusing on nearer things cause myopia? See if you're curious at even a basic level, you'd realize that there are important *details* about stuff like this where it actually helps to have some actual subject matter expertise and knowledge.
I believe during a certain age range your eyes determine they've grown to the correct size based on how well they focus, and ancestral humans mostly focused at far away things. When we spend lots of time indoors and looking at screens, our eyes adapt to this as the default focus. Since they're also evolved to look at things nearer than the default focus but not farther (since it's meant to be at infinity), this creates myopia.
That's a lovely theory, if quite imprecise in terms of the actual biology of eye development. The actually important part of science (the part that requires a lot of expertise and judgement) is figuring out how to make that an actually testable hypothesis and then whether or not its true.
>if quite imprecise in terms of the actual biology of eye development
Explain how, please.
> a certain age range your eyes determine they've grown to the correct size based on how well they focus
A certain age -> which one? Why?
your eyes determine -> How? What molecular growth signaling pathways are involved? How do they integrate with your brain's visual processing centers and how does that relate to "how well [your eyes] focus". Is there a biomechanical signal from muscle stress or eye curvature?
How would you test this? You'd have to change this process somehow to show that the effect is real, but you obviously can't do that with humans, so you'd probably have to use mice, but their eyes are different, but how so?
Without any of this information, it's a nice "just-so" story about cavemen looking at the horizon, but not much more than that.