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
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
The colossal squid has the largest eyes in the world.
4
The human eye blinks an average of 4,200,000 times a year.
233
Tigers can see 6 times better at night than humans.
305
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