1. Just behind our pupil is the lens - which is round, flat and thicker toward the middle.
2. Your eyebrows prevent sweat dripping into your eyes.
3. Eyelashes have an average lifespan of five months.
4. If you lined up all the eyelashes shed during one human life, they would measure 98 feet long.
5. Newborn babies can see objects about 8-15 inches away most clearly.
6. The only cells that survive from the time you are born until death are in your eyes.
7. Colour blindness is more common in males.
8. A newborn baby will cry, but not produce any tears. Babies do not produce tears until they are around six weeks old.
9. All babies are colour blind at birth.
10. Contrary to urban myth, contact lenses cannot become 'lost' behind your eye due to the structure of your eyeball.
11. Heterochromia refers to a condition where eyes are two different colours.
12. Diabetes is the number one cause of blindness in adults in the UK.
13. Research has found that a tie tied too tightly can increase the risk of glaucoma in men.
14. Blue-eyed people share a common ancestor with every other blue-eyed person in the world.
15. During a sight test, health conditions including diabetes and high blood pressure can be detected.
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16. Blind people can see their dreams as long as they weren't born blind.
17. In a very basic form, eyes are thought to have first developed in animals around 550 million years ago!
18. 94% of visible premature-aging around the eyes is caused by UV damage.
19. The older we get, the less tears we produce.
20. When you read or stare at a computer, you blink less often resulting in tired eyes.
21. About half of the human brain is dedicated to vision and seeing.
22. People generally read 25% slower on screen than on paper.
23. One of the most common cosmetic injuries is poking the eyeball with a mascara wand.
24. Our eyes close automatically to protect us from perceived dangers.
25. Our eyes have small blind spots where the optic nerve passes through the retina, and our brains use the information from the other eye to fill this gap.
26. Everyone has one eye that is slightly stronger than the other.
27. In an average life, your eyes will see 24 million different images.
28. The human eye only sees three colours: red, blue and green. All other colours are combination of these.
29. Eyes are able to process 36,000 pieces of information in a single hour.
30. Some people have a fear of eyes; it's called ommatophobia.
31. The eyeball weighs around 28 grams.
32. Smoking reduces your night vision.
33. 80% of vision impairment worldwide is curable.
34. Your nose gets runny when you cry as the tears drain into your nasal passages.
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35. Oily fish, vitamin A and vitamin C can all help to preserve good eyesight.
36. Albinism affects melanin production; perhaps resulting in extra sensitivity to light and a red-eyed appearance.
37. Astigmatism refers to a curvature of the cornea or lens and toric lenses are prescribed to aid the individual's vision.
38. When your eyes are watering it may be a sign of dry-eye, and your eyes are producing more moisture to compensate.
39. The shark cornea is nearly identical to the human cornea, and has even been used in human eye surgery!
40. Heterochromia is the medical term for having two different colored eyes.
41. Your eyes are comprised of rods and cones. Rods allow you to see shapes, while cones are responsible for detecting and deciphering colors.
42. Your eyes can detect a candle flame 1.7 miles away.
43. Your iris (the colored part of your eye) has 256 unique characteristics; your fingerprint has just 40.
44. 80 percent of all learning comes through the eyes.
45. Eyes are the second most complex organ after the brain.
46. Your eyes focus on 50 different objects every second.
47. "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.
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48. 80% of what we learn is through our eyes.
49. A fingerprint has 40 unique characteristics, but an iris has 256, a reason retina scans are increasingly being used for security purposes.
50. People who are blind can see their dreams if they weren't born blind.
51. 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.
52. 80% of our memories are determined by what we see.
53. Corneas are the only tissues that don't have blood.
54. An eye is composed of more than 2 million working parts.
55. Only 1/6 of the human eyeball is exposed.
56. Eyes began to develop 550 million years ago. The simplest eyes were patches of photoreceptor protein in single-celled animals.
57. Your eyes start to develop two weeks after you are conceived.
58. Despite your eyes being at the front of your head, the part of your brain that handles seeing is actually at the back of your head.
59. Spectacles had been treating long-sightedness for around for 300 years before anyone could learn to correct short-sightedness.
60. 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.
61. Although the function of tears is to keep eyes clean, scientists don't understand why we cry when we are upset.
62. If you saw everything upside down, your brain will stop flipping the images your eyes send them, so you can see the right way up.
63. 80% of vision problems worldwide are avoidable or even curable.
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64. Eyes contain around 107 million light-sensitive cells.
65. Each of your eyes has a small blind spot in the back of the retina where the optic nerve attaches. You don’t notice the hole in your vision because your eyes work together to fill in each other’s blind spot.
66. Out of all the muscles in your body, the muscles that control your eyes are the most active.
67. Even if no one in the past few generations of your family had blue or green eyes, these recessive traits can still appear in later generations.
68. Around the world, about 39 million people are blind and roughly 6 times that many have some kind of vision impairment.
69. Doctors have yet to find a way to transplant an eyeball. The optic nerve that connects the eye to the brain is too sensitive to reconstruct successfully.
70. If the human eye was a digital camera, it would have 576 megapixels.
71. On average, you will blink approximately 4,200,000 times in a single year.
72. The human eye can function at 100% at any given moment, without needing to rest.
73. The eye is the fastest muscle in your body – hence why when something happens quickly, we say "in the blink of an eye!"
74. A blink typically lasts 100-150 milliseconds.
75. In a single second, it's possible to blink five times.
76. You are likely to blink more often when you are talking.
77. You actually see with your brain, not your eyes. Our eyes function like a camera, capturing light and sending data back to the brain.
78. You see things upside down - it is your brain which turns the image the right way up.
79. Brown eyes are blue eyes underneath. Consequently, a person can receive surgery in order to make their brown eyes blue.
80. Each individual eye contains 107 million cells and all are light sensitive
81. The human eye can differentiate approximately 10 million different colors.
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82. The muscles which help your eyes to focus complete around 100,000 movements a day. In order to make your leg muscles do the same amount of movements, you would need to walk 80 kilometres.
83. People with blue eyes are more sensitive to pain than others.
84. Priests in ancient Egyptian temples plucked every hair from their bodies, including their eyebrows and eyelashes.
85. You blink your eyes over 10,000,000 a year.
86. Your tongue, eye, and jaw muscles are among the strongest muscles in your body.
87. It takes the human eyes an hour to adapt completely to seeing in the dark. Once adapted, however, the eyes are about 100,000 times more sensitive to light than they are in bright sunlight.
88. Blue eyes are the most sensitive to light, dark brown the least sensitive.
89. While reading a page of print the eyes do not move continually across the page. They move in a series of jumps, called "fixations," from one clump of words to the next.
90. The farthest you can see with the naked eye is 2. 4 million light years away! (140,000,000,000,000,000,000 miles.) that's the distance to the giant andromeda galaxy. You can see it easily as a dim, large gray "cloud" almost directly overhead in a clear night sky.
91. Human eyes are so sensitive that on a clear night when there is no moon, a person sitting on a mountain peak can see a match struck 50 miles a way.
92. A healthy (non-colorblind) human eye can distinguish between 500 shades of gray.
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93. Every person, including identical twins, has a unique eye and tongue print along with their finger print.
94. If you go blind in one eye you only lose about one fifth of your vision but all your sense of depth.
95. If you keep your eyes open by force when you sneeze, you might pop an eyeball out.
96. As you get older, the lens in your eye grows thicker - this is why people who had perfect vision when younger need glasses as they advance in years.
97. Your eyes are constantly moving, usually in rapid jerky movements. But your brain has a kind of ‘steadycam’ feature which makes your vision seem to be stable.
98. When you were born you had blue eyes. It was only after exposure to light that they became the colour they are now.
99. Around half the population of the world have eyelash mites - tiny creatures that live on your eyelashes and eat dead skin cells. If you put your eyelash under a microscope, you might just see one!
100. In an experiment, people were given glasses which flipped their vision upside down. Within a day, those people’s vision had corrected itself so the brain interpreted the world the right way up. Amazingly, when the glasses were eventually removed, the same thing happened - it took around a day for the brain to adjust again.
101. Even the tiniest of noises automatically makes your pupils change focus.
