[scottshamus]

It may not be related to nature. I remember reading research on how sunlight and focusing on distant objects is really important for developing proper eyesight. The current issues with eyesight could be a side-effect of spending more time in doors and only staring at things within 20 to 30 ft.

https://www.canr.msu.edu/news/the_benefit_of_daylight_for_ou...

[barbariangrunge]

30 foot line of sight indoors, more like 1-5 feet for most people working at computers