1. Vision provides a person with 90% of the information he receives about the world around him.
2. The iris has 256 unique characteristics, making security systems associated with iris scanning considered more reliable than those that scan fingerprints. The prints have only 40 unique features.
3. When exposed to light, the pupil of the eye gets smaller, protecting the retina from damage. In the evening, on the other hand, the pupil gets bigger to let more light into the eye.
4. Human peripheral vision has very low resolution and almost no color. Also the peripheral vision in women is much better than in men.
5. The human retina is only 0.05 to 0.5 mm thick, but it is divided into 10 microscopic layers.
6. Too bright lighting is no less harmful to vision than lack of light.
7. Human is the only animal that cries under the influence of strong emotions. In other living organisms, tears are needed only to cleanse the eyes of foreign objects and wet them.
8. The retina of the human eye perceives the world upside down, and then the resulting image turns the brain. In addition, the eye receives an image divided into halves and significantly distorted, and the brain puts it together.
9. All blue-eyed inhabitants of the Earth are the descendants of one ancestor who lived about 6,000 years ago. Initially, all people who inhabited the Earth had brown eyes.
10. We blink about 7,900,000 times a year, or about 15 times a minute.
11. Newborn babies distinguish objects at a distance of about 40 centimeters.
12. The human eye weighs about 7 grams, and most people's eyeballs are 24 mm in diameter.
13. A person cannot sneeze without closing their eyes.
14. Women, according to statistics, cry about 40-50 times a year, men about 5-7.
15. Human tears have a different chemical composition depending on whether a person suffers, rejoices, yawns, or removes a speck from the eye.
16. Human eyes are fully formed by the age of 7 and have not changed their structure and size since then.
17. Every twelfth man is color blind, i.e. does not distinguish between one or more colors. Congenital color blindness is inherited from mother to son, so there are 20 times less color blindness among women than among men.
18. The eye muscles are the most active in the human body, since they constantly make micro-movements that a person simply does not fix.
19. Each of us has a "dominant" and "non-dominant or driven" eye - by analogy with the hands.
20. Why PIRATES wear Eyepatches?
• The image of a pirate with an eye patch appeared for a reason: in fact, having a patch does not mean losing an eye.
• Medieval sailors from among those who constantly moved between deck and hold (especially during battle) wore such bandages to quickly adapt their vision to darkness. When they left the brightly lit deck inside the dark hold, they simply lifted the bandage and could immediately distinguish the details, and not spend a few minutes each time adapting.
• Humanly, the eye gets used to the darkness for a long time: in the first minute after the transition from light to darkness, the sensitivity to light increases only 10 times, after 20 minutes - 6000 times! But even after that, the eye continues to adapt to the dark: complete addiction occurs only after an hour or an hour and a half.
• So if they wear Eye patches, It will help them to work in both environments immediately.
21. The lifespan of each eyelash is about 5 months. We do not record a massive loss of eyelashes, because most of them “fall off” imperceptibly: during sleep, when washing, etc. Therefore, it seems to us that eyelashes fall out much less often. In total, each eye (on the upper and lower eyelids) has about 150 eyelashes.

Animal Related Eye Facts

• There are many living species on the planet, the number of eyes is different from the norm. For example, most spiders have 8 eyes, some scorpions have 12, and the dragonfly generally has faceted eyes, consisting of hundreds of separate "eyes" (the images from which are added to the picture already in the insect's head).
• Many animals have only partial color vision. So, cats do not distinguish red, and dogs - also yellow, orange. The same goes for insects. But some of their types perfectly distinguish ultraviolet light inaccessible to humans.
• The viewing angle (field of view) of a person is on average 160-200 degrees. In goats and sheep with horizontally located rectangular pupils, the angle of vision is increased to 240 degrees. And the horse is able to notice almost everything around him: its field of view covers 350 degrees! The narrowest viewing angle in dogs is only 30-40 degrees.
• The expression "eyes like an eagle" is no coincidence: the visual acuity of a feathered predator is twice that of a human. Eagles, falcons and golden eagles are able to see a target 10 cm in size from a height of 1-1.5 km. This property helps them a lot while hunting.
• Some animals (ducks, dolphins) can sleep with one eye open. This ability is dictated by safety considerations: while one half of their brain is resting, the other is making sure that no predators sneak up.
• The largest eye is that of a blue whale, it weighs about a kilogram.
• In herbivores, the eyes are located on the sides of the head to better see the danger, and in predators, in the front, so as not to lose sight of the prey.

These all details in just for basic information about the diseases. Please consult your doctor before following this by yourself. --- Dr Dhaval Patel (MD, AIIMS Delhi)

- compiled & published by Dr Dhaval Patel MD AIIMS