Comment by MyPasswordSucks

I'd be interested to see sources for the claim that poor eyesight is evolutionarily recent.

I strongly suspect it's more a matter of "won't kill you". Nearsightedness is far more common than farsightedness, and it's only in the last two hundred or so years that there's been any major benefit in seeing fine details at distance. The fuzzy shapes afforded by 20/80 vision are plenty enough to hunt a mammoth.

Having 20-20 vision is nice for avoiding lions and tigers, but it's a luxury spec, because movement acuity doesn't decrease linearly with nearsightedness, and movement acuity (plus traveling in groups, as prehistoric humans were wont to do) can take care of business decently-enough on its own - so I wouldn't call it "evolutionary-pressure"-nice.