It seems to me that poor vision would have been a big evolutionary disadvantage; if Grok couldn't see a lion coming, he wouldn't have reproduced and we wouldn't be here. I saw a bunch of documentaries from the 70's and most of the people had glasses. Nowadays, many people (uncluding myself) wear contact lenses. So I'm hypothesizing that this is due to our change in diet.
Can anyone help compile research for or against this? I'll keep searching, this idea just came to me, and I wanted to post it before I forget.