Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Those things you see in your eyes when you stare into space are called Mouches Voltanes, which are also broadly referenced to as Floaters.
9
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
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
There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22
Tigers can see 6 times better at night than humans.
305
The human eye blinks an average of 4,200,000 times a year.
233