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
Tigers can see 6 times better at night than humans.
305
The human eye blinks an average of 4,200,000 times a year.
233
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
Only about 2% of the world population has green eyes.
36
There's a woman named Veronica Seider who had vision 20x better than average. She could identify people more than a mile (1.6km) away.
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
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
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