Myopia (nearsightedness) is becoming a major problem in today's world. Many "professionals" will say its all genetic and there is nothing you can do. This is a blatant lie, the eyesight problems of humans in modern civilization is entirely from misuse of our eyes. Our ancestors didn't spend hours upon hours looking at screens close to their face. There have been studies done about eskimos regarding eyesight. The parents that lived a natural life, virtually none of them had eyesight problems. But whne schools were introduced for the kids myopia rates started to skyrocket..
I believe you are correct. Your health is a factor of two things - nature and nurture.
Nature is your genetics... eyes have been evolving and getting better for a billion years. There is no reason they suddenly would reverse.
Nurture is how you treat yourself - I've been starting at computer screens for 35 years now, and I just needed (yesterday) to get glasses - and just because of age. I obviously have good DNA, as many others will damage their eyes just starting at computer screens for a couple years.
I nearsighted and for many years I didn't use glasses. It only got worse. So I don't know if glasses really messes them up. I also tried playing video games with an eye patch, to work my weaker eye. That didn't help much.
My optometrist told me yesterday that using glasses does not deteriorate your eyesight. When people complain they can no longer see without glasses, it is because they have become accustomed to using the glasses.