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
Only about 2% of the world population has green eyes.
36
There are so many kinds of apples that if you ate a new one everyday, it would take over 20 years to try them all.
34
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82