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
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
Tigers can see 6 times better at night than humans.
305
The colossal squid has the largest eyes in the world.
4
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