Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Sheep, goats, octopuses, and toads have rectangular pupils.
7
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
In ancient Egypt, priests plucked EVERY hair from their bodies, including their eyebrows and eyelashes.
130
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
Tigers can see 6 times better at night than humans.
305