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
In one day, adult lungs move about 10,000 litres of air.
11
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.
21
You can hear the blood flowing through your ears if you find a quiet place and cover them tightly.
17
The human brain uses approximately as much energy as a 10 watt light bulb.
120
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
There's 100 trillion good bacteria living in your body.
17
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515