Why Are You Nearsighted? Here's An Explanation You May Not Have Heard.

Nearsightedness is reaching epidemic levels worldwide, but nowhere is its rise more prevalent than East Asia, where as many as 90% of teenagers and young adults now suffer from blurry distance vision. Why the sudden spike? Book work has long been blamed, but recent findings point to something else. » 3/18/15 3:20pm 3/18/15 3:20pm

Why can't humans see underwater?

If you've ever dunked your head underwater sans goggles in search of a set of keys or a pool toy, then you know how difficult it can be for the human eye to make sense of light in a subaqueous environment — but you might not know why this is. » 1/03/12 7:15am 1/03/12 7:15am