Just like any other organ in our body, the human eye is also a complex system that provides us with a vision. Eye works on a simple principle; they detect light and then change it to electro-chemical impulses and send it to the brain. The transmission of these signals also has their own tales.
The signals are sent to the brain through complicated neural pathways, which is extended between the optic nerve and the visual cortex. Complex eyes, just like the ones we have, can distinguish various shapes and colors and other complex works while simple eyes like those of the microorganism can just detect light.
I think thus far we know how important the eyes really are. So why not we know something about it. Below are some of the facts about eyes that you may not know.
28. One might be amused to know that a human eye has no less than 2 million distinct working components, which by the way is directly responsible for about 85% of our total perceived knowledge about a subject matter.
27. The skin between our eyebrows is known as Glabella. Whereas Naison is the point of intersection between the frontal bone and two nasal bones, sitting in the depressed area directly between the eyes.
Side view of a human head
26. According to the World Economic Forum, every year the world economy slips more than $227 billion because of nearly 35% of the world population who cannot see without proper glasses. Due to their poor, unaided eyesight, they face difficulties in education and are denied in jobs.
25. There are many animals and insects that have more than two eyes. Animals such as spiders have 8-12 eyes, box jellyfish on the other hand possess 24 simple eyes that only detects light and dark.
24. Have you ever wondered why humans and dogs have so much better understanding with each other? Well, one reason is because Humans and dogs are the only two species on Earth, which are capable of seeking visual clues from one another through the eyes.
23. A Chameleon can rotate its eyes in two different directions at the same time.
22. Do you know that we spend almost 10% of our total walking time with eyes completely shut? Yes, we do, and the logic behind is that an average person blinks some 15-20 times per minute.
21. Compared to their brain, Ostriches have much bigger eyes.
20. Famous American comedian Ben Turpin had his eyes insured for US$100,000. Ben Turpin, who is popular for his cross-eyes actually secured his eyes with a hefty insurance backup. In any case, if his eyes were to become normal, the money would be payable to his producer Mack Sennett.
19. Fear of eyes anyone? Ommetaphobia is a fear of eye care. Generally, this problem can be a direct outcome of severe eye-related trauma during the childhood or being exposed to some gruesome images at some point of time.
18. A rare benign tumor designated as “limbal dermoid” can cause small hair to grow near the eyeball. On another note, this tumor can cause astigmatism, a common eye condition where normal vision is blurred.
17. Keeping lens in your eyes of elongated time can damage your eyes entirely. A few years ago in 2014, a Taiwanese student lost her eye after she wore the same lens for the straight 6 months. Apparently, a microscopic bug that spawned because of the lens, ate her eye balls.
16. The Kayser–Fleischer ring is an eye condition, where dark rings appear in the iris of the eye. They occur in an extremely rare genetic disorder known as Wilson’s disease.
Copper disposition on corneal Descemet’s membrane
15. Do you think that carrots improves your eyesight? If yes, then it’s time to change your thinking. In reality, carrots are as good as other green vegetables for our eyes. This myth was possibly started by the British pilots during the World War II to keep Germans from getting their hands on the all-new RADAR technology.
14. Why all the night vision goggles are green, do you know? Well, it is simply because human eyes are far more sensitive to green color than almost any other color which helps us differentiate more shades of green accurately.
13. Some lizards such as horned ones, shoots blood out of eyes and use it as a vital defense mechanism against predators. When threatened, horned lizards try to confuse or scare their predators by ejecting a guided stream of blood towards them. There are at least eight known species of horned lizards which are capable to shoot blood.
12. The largest eye in the animal kingdom is not of a blue whale but the giant squid. Also known as the largest invertebrate, their one eye is about the size of a volleyball.
11. Our eye is connected with the brain with a complex web of muscle, blood vessels and more 1 million nerve fibers. This makes transplantation of the entire human eye next to impossible. The only part of our eyes that can be transplanted is a Cornea, through the process of corneal grafting.
10. Sclater’s lemur, commonly known as Black lemurs are possibly the only primates, apart from humans, that possess blue eyes with variations. Normally, their eyes can be from light-sky blue color to appalling electric blue.
Blue eyed black lemur Image Courtesy: Bruce McAdam
9. Amblypia or what we commonly know as a “lazy eye” is generally treated by patching the dominant eye and the weaker eye calibrates on its own. But researchers at the McGill University has discovered that the popular video game Tetris can be successfully used to train both eyes to work together, hence providing a better alternative to patching.
8. Humans have three different channels for gathering color information which is derived from the presence of three separate cone cells in our eye. This state of the eye is known as trichromaticism and it allows us to perceive 10 million different colors.
7. According to an article in the nytimes, about half of the American population born in the beginning of the 20th century had blue colored eyes. However, in the next 50 years or so that number dropped down only to a third. In the 21st century there are about two in twelve Americans have blue eyes. Pretty rare, right.
6. A human baby is born with roughly 75% of actual size of an adult human eye. Internal eye structure, optic nerve and visual functions in overall continues to develop at a fast pace during the first two years. Furthermore, a newborn generally has an eyesight of about 20/400, which gradually improves to perfect 20/20 by age 2.
5. According to a research conducted in 2012, a small number of females might be able to see 100 million colors that are completely invisible to the rest of us. This condition is known as Tetrachromatic vision, which is generally found in specific types of fish and birds. A woman with Tetrachromatic vision are supposed to sustain three normal cone cell along with one mutant type.
4. Do you know about how many megapixels equivalents does the human eye have? Well, in short 567 megapixels. The human eye is more like a video camera, where it moves rapidly in small angular positions and send new images to the brain. The combine signals of our eyes, then further increases the resolution.
3. It’s a common knowledge that Albert Einstein’s brain was removed from his body by pathologist Thomas Harvey upon his death, but are you aware that his eyes were also removed? Yes, Thomas Harvey also removed Einstein’s eyes and handed them to Henry Abrams. It is now in a safe box in New York City.
2. The study of evolution of eye gain attraction of the scientific community in the early 1800s. The earliest fossils of eye found till date is believed to be about 600 million years old during the lower Cambrian period. This period witnessed a phase of unprecedented diversification in the animal phyla, it is also known as the “Cambrian explosion.”
Zoologist Andrew Parker has proposed that the evolution of eyes has helped shape the current relationship between a predator and prey and initiated the evolutionary arms race.
Schematic diagram of the evolution of the eye.
1. Of all the eye colors, green is perhaps the rarest color found in the world. According to an estimate, only 2% of the total world’s population have green eyes. The green color is actually a result of a mixture of a mild pigmentation, a golden tint, combined with blue scattering of the eye (Willis-Tyndall scattering).