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
The colossal squid has the largest eyes in the world.
4
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
Sheep, goats, octopuses, and toads have rectangular pupils.
7
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