Rates of myopia are skyrocketing. Current research shows one possible reason behind the rise in rates of myopia (short-sightedness) since the industrial revolution is lack of bright sunlight during eye development, but this is very recent and as such has not been conclusively proven.

While waiting for new answers, could check out the older discussions in the FAQ

Also, how important is good vision for survival throughout the ages? I don't imagine that the precision that is today's standard, that is being able to read text both close and far away, is essential for hunting, gathering, farming, or repetitive tasks.