We don’t often give our eyes as much thought as we should, that is until something goes wrong and our vision is affected. But when you learn more about eyes, you realize just how amazing they are. Here are a few facts you may enjoy:
1. Eyes began to develop 550 million years ago. The simplest eyes were patches of photoreceptor protein in single-celled animals.
2. Your eyes start to develop two weeks after you are conceived.
3. The entire length of all the eyelashes shed by a human in their life is over 98 feet with each eye lash having a life span of about 5 months.
4. To protect our eyes they are positioned in a hollowed eye socket, while eyebrows prevent sweat dripping into your eyes and eyelashes keep dirt out of your eyes.
5. Your eyeballs stay the same size from birth to death, while your nose and ears continue to grow.
6. An eye is composed of more than 2 million working parts.
7. Only 1/6 of the human eyeball is exposed.
8. Corneas are the only tissues that don’t have blood.
9. The human eye weights approximately just under an ounce and is about an inch across.
10. An eye cannot be transplanted. More than 1 million nerve fibers connect each eye to the brain and currently we’re not able to reconstruct those connections.
11. 80% of our memories are determined by what we see.
12. Eyes heal quickly. With proper care, it takes only about 48 hours to repair a minor corneal scratch.
13. There are about 39 million people that are blind around the world.
14. 80% of vision problems worldwide are avoidable or even curable.
15. Humans and dogs are the only species known to seek visual cues from another individual’s eyes, and dogs only do this when interacting with humans.
16. A fingerprint has 40 unique characteristics, but an iris has 256, a reason retina scans are increasingly being used for security purposes.
17. People who are blind can see their dreams if they weren’t born blind.
18. “Red eye” occurs in photos because light from the flash bounces off the back of the eye. The choroid is located behind the retina and is rich in blood vessels, which make it appear red on film.
19. 80% of what we learn is through our eyes.
20. Eyes are the second most complex organ after the brain.