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
The average person's skin weighs twice as much as their brain.
131
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
All humans have the ability to see ultraviolet light, but it is passively filtered out by the eye's lens. People who undergo surgery to remove the lens can detect ultraviolet light.
22
The human sigh acts as a physiological reset button.
23
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193