There are glasses which allow a red-green color-blind person to see colors the way everyone else does.
22
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
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 sperm cell swims at 8 inches per hour.
76
Your body is creating and killing about 2.4 million red blood cells per second.
17
There's 100 trillion good bacteria living in your body.
17
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118