Cowboys / sailers in the crow's nest / hunters in all stories seem to be able to see tiny things on the horizon. Is that just for the story's sake or have our developments in glasses / vision systems made us less reliant on our own eyes (and as such we don't use them to the extent that they used to).
Recent studies have shown that a lack of outdoor time dramatically increases myopia (nearsightedness) http://www.nature.com/news/the-myopia-boom-1.17120
The study was prompted by doctors noticing that our eyes are way worse today than in the past, and the rate at which they're going bad is speeding up.