Or are we detecting eyesight issues earlier, which we did not do in the past, and prescribing correction glasses?

I want to think it's this. My anecdotal data point is I was outside nearly every day as a child and I assumed my vision was fine. It wasn't until 2 years into university that I had my vision checked and got my first prescription and it was night and day better. I imagine there's a great deal of people that don't know they should get prescribing correction glasses.

I have a theory, I think the problem is the lack of range of eyes muscles. Most people who needed glasses are people who are not usually seeing long distance objects, these people usually stays in a confined space or usually reading or using cellphones, eventually the muscles used to focus objects becomes limited in range of motion. Imagine a camera who cannot focus, because of a failure resulting in a limited range of motion. Despite having no problems with the lenses, the camera remains out of focus this resulting in blurriness. I do think people need to get out, see long distance objects, not just remain in a confined space with close proximity objects like walls,etc. My vision returned to 20/20 after ditching eyeglasses and going outside, and if I am inside the office I picked location near windows and relax my eyes looking at distant objects.

Kids ain't getting outside enough.

I'm afraid we'll be in that boat too. My toddlers walk outside every day but it's harder in winter.

I've been near-sighted from a young-ish age (around 10 or so). I can't see anything more than a foot away without glasses, but I can focus on things that are barely an inch from my face.

I don't think it was necessarily caused by computers. I was born cross-eyed, and my right eye experienced neurological death by the time they got fixed.

Now I can only read (easily) from my left eye (even though my right eye is perfectly sharp!) and it's impossible for me to experience motion sickness in VR (which is a benefit, I guess).

It is a really weird feeling to be able to resolve every detail on an eye chart, but not be able to say which letter it is :(

Not just Glasses, but Braces as well

Take a look at pictures--not movie stars, but ordinary people--from before about 1950. You will see a lot of people who'd have had braces, were they born later (and of course to sufficiently prosperous parents).

animals that operate in the dark tend to have bad vision

their counterparts that operate under the sun tend to have good vision

is there causal effect? or just correlation that light intensity matters?