We register over 90 % of total incoming information with our eyes. Eye lens act as filter of the ultraviolet light. If surgically removed, retina can detect it.
Reading in feeble light will not do any harm to your eyes. If elderly people at one moment start reading without eyeglasses, they should get their eyes checked for cataract development. Blink lasts less than 1/10th of a second. Women blink more often than men. Several million times a year. The more you talk, the more you blink. Eyes can heal a corneal scratch in just two days. Tears first appear at age of 1-2 months. Up to 50 million people in the world can’t see. Eye colour, similar to skin colour, depends on the amount of melanin. Biggest obstacle for a successful eyeball transplant is the complexity of the optic nerve. Rod-shaped cells in your eye detect shapes, and cone-shaped cells: colour. People with heterochromia have two differently coloured eyes. Each eye has a blind spot. Muscles, controlling your eyes, perform most movements. Most wide-spread eye colour is brown. Dogs see colours differently than humans, not distinguishing clearly green, yellow or red. Diabetes can cause blindness. You read up to 25% slower from a computer screen than on paper. Brain of the ostrich is smaller than any of its eyes. Eyelashes are renewed twice a year. Colossal Squids have eyeballs almost one foot in diameter (28 cm). Some people can see a candle light from 14.5 miles (over 20km). There have been attempts to transplant shark cornea to humans. Cornea takes the oxygen needed from air, as it has no own blood supply. After brain, eyes are the most sophisticated body part. The Mayans did not spare efforts to make their children become cross-eyed. Most colour blind people are men. Your eyebrows are separated by what’s called the Glabella. Only 15% of human eyeball is exposed. Quantity of tears diminish with age. Your eyes have around 125 million light sensitive cells. Normally one of your eyes is stronger than the other. When crying, tears drain into nasal passages and nose gets runny. Iris is 8 times more unique than fingerprint. Red-eye effect on pictures is caused by the capillaries in your eyes. A necktie too tight doubles the risk of glaucoma. When sneezing, eyes involuntarily close. Blinking uses more than 200 muscles. Human eye has still better resolution than digital cameras on the market. The special enzyme in tears lysozyme is capable of destroying most bacteria.