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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
There's a woman named Veronica Seider who had vision 20x better than average. She could identify people more than a mile (1.6km) away.
22
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
Poor eyesight (myopia) is associated with higher IQ.
232
There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22