Poor eyesight (myopia) is associated with higher IQ.
232
Tigers can see 6 times better at night than humans.
305
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
All humans have the ability to see ultraviolet light, but it is passively filtered out by the eye's lens. People who undergo surgery to remove the lens can detect ultraviolet light.
21
Sheep, goats, octopuses, and toads have rectangular pupils.
7
The human eye blinks an average of 4,200,000 times a year.
233
There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22