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
Your hair grows faster in the morning than at any other time of day.
91
The right lung takes in more air than the left.
30
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
While 7 men in 100 have some form of color blindness, only 1 woman in 1,000 suffers from it.
50
The human brain doesn't stop developing until about 25 years old.
102
Smokers get ten times more wrinkles than non-smokers.
171