25 Side-Knowledge About Eyes You Don't Know
People often say that eyes are the windows to the world and the door to the soul. But how much do you know about it? Do you know how heavy your eyes are? Do you know that brown eyes can permanently turn into blue eyes? Today we will share 25 side-knowledge about eyes you don't know.
1. Human cornea is very similar to that of a shark, so which is often used as a replacement for the human cornea in surgery.
2. All newborn babies are color blind. When children are just born and open their eyes, their world is mainly composed of three colors: black, white and gray.
3. Scientists at the University of Copenhagen have discovered that people with blue eyes have a common ancestor. This ancestor had a blue mutation and lived between 60,000 and 10,000 years ago. Before this period, everyone had brown eyes.
4. People with brown eyes actually have brown pigment covering the blue. There is a laser surgery which can permanently turn brown eyes into blue eyes.
5. Human eye can distinguish 500 different shades of grey.
6. There are about 107 million light-sensitive cells inside each eye.
7. One in 12 men suffers from color blindness.
8. The most eye color in the world is "brown".
9. Most parts of our body need a certain time to re-run and stimulate their potential, but eyes are active in 24 hours a day.
10. The average anterior and posterior diameter of eyeball of a normal adult is 24 mm, and the average vertical diameter is 23 mm, weight is 8g.
11. Muscles that control the eyes are the most active in all the muscles in the body.
12. There is a small blind area behind retina of each eye, where optic nerve is connected. The reason you can't feel it is the compensatory effect of the other eye.
13. Human eyes remain the same size from birth, from 19 to 24mm in length, while ears and nose are constantly growing in terms of multiples.
14. Most people think that tears are only composed of water. In fact, tears are mainly composed of fat, mucus and water.
15. Although only one-sixth of the human eyeball is exposed, it is the only organ exposed to the air.
16. When people read on a computer screen, they are 25% slower than reading on a newspaper.
17. Eye can process approximately 36,000 bits of information per hour.
18. Eyes can focus approximately 50 times per second.
19. With proper care, eyes can heal quickly. If the cornea is scratched, it only takes about 2 days to heal.
20. Eyes blink 17 times per minute on average, 14280 times a day, 5.2 million times one year. They blink more frequently when speaking than when reading.
21. The focusing speed of the eyes is faster than that of any camera.
22. Eyes are one of the earliest organs. At 8 weeks after the embryo, baby’s eyes begin to develop.
23. Studies have shown that people with severe depression see reduced color contrast, which makes colors in their eyes are darker than they actually are.
24. We look at things with our brains instead of our eyes, which sounds incredible. In many cases, blurred vision or decreased vision is not caused by the eyes, but by the visual cortex of the brain.
25. On average, each fingerprint has 40 unique features, while iris of the eye has 256. Therefore, retinal scanning is increasingly used in many fields such as security inspections.
