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
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21
Tigers can see 6 times better at night than humans.
305
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Poor eyesight (myopia) is associated with higher IQ.
232
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22