Human are highly visual beings. Most information captured in our brains is seen through our eyes. We often don’t think much about our eyes, yes, that is until something goes wrong and we realize how vital they are. Our eyes are just not objects of expressing our feelings and emotions; they are way more than that. Here are a few amazing facts about human eyes that will make you realize just how incredible they are:
1. The eye is the second most complex organ in our body (after the brain)
Our eyes are made up of more than 2 million operational parts which can process 36,000 bits of information per hour! How cool is that?
The eye comprises of complex mechanisms and pathways and with the help of several structures like the cornea, retina, iris, pupils, optic nerves and the ciliary muscles. All these parts work together to help the eye function properly and make our vision perfect. Quite awesome huh?
2. Your retinas actually perceive the outside world as upside-down – your brain flips the image for you.
Just imagine how it would be to look at the world upside down. Well, guess what, you actually do. Your retinas are made such that they capture the image you see upside down but the brain flips the image for you. Now I know you can’t even start to fathom how fast that happens since you always see all the images upright even at a quick glance.
If you ever want to see the world just like your retinas do, simply try a pair of prism glasses. In addition to being upside-down, images arrive at your retina distorted and split in half. Each half of your brain then receives these images, unscrambles them and then puts the two images together to make you see a complete image.
3. The eye muscles are the strongest in our body
The external muscles in the eye are by far the strongest and the most active in our body. Though the external muscles of the eye are fairly large in relation to the weight and size of the eyeball when it comes to strength, nonetheless, they are the strongest muscle for the job. Why so? The muscle of the eye is made such that it constantly move to readjust the position of the eye even when our head is in motion.
Other than that, did you know that our eyes also work while we are asleep? During REM the Rapid Eye Movement Sleep our eye muscle moves constantly. However, our eyes are still subject to fatigue too. Thus, our eye needs rest after working constantly for an hour.
4. Your retinas cannot detect the color red
Although retinas usually have blue, green and red receptors, they do not detect the color red. The red receptor only detects yellow- green and while the green receptor detects blue-green. Our brains then work to combine these signals and deliver the color red image.
5. We blink 25,000 times a day
A large number don’t you think? And an average blink lasts 1/10th of a second. A blink usually lasts 100 to 150 milliseconds, also, it’s possible to blink five times in a second. Did you know blinking has a purpose? We blink for two reasons: to protect our eyes from any foreign materials and to keep our eyes always lubricated.
6. The eye require no rest
Eyes are the only organs in the human body that can work constantly and function 100% at any moment night or day without the need for rest. However, it is recommended to give your eyelids, and the external muscles of your eyes some rest to enhance proper functioning.
7. If you’re farsighted, your eyeball is shorter than average, however, if you are shortsighted, your eyeball is longer than normal.
Most people think that to be shortsighted your eyeball must be shorter than normal and the vice versa quite the irony right.
8. Each eyelash has an approximate lifespan of 5 months
The entire length of all the eyelashes shed by a human in their life is over 98 feet with each eyelash having a lifespan of about 5 months.
9. Eyes heal quickly
Eyes are designed to heal very quickly. Why? When the outer layer of cells on an eyeball are injured, cellular replacement takes place rapidly because the surface of an eyeball contains living cells. These living cells have the ability to migrate and reorganize themselves to the place where cells were lost and heal it. With proper hygiene care, it only takes about 48 hours for the eye to repair a corneal scratch.
10. Your eyes are almost the same size as they were when you were born
Your eyeballs stay the same size from the day you are born to the day you die. While the nose and ears continue to grow.
Fun facts about Newborn eyes
• Newborns don’t produce tears. They make crying sounds, but the tears don’t start flowing until they are about 4-13 weeks old.
• Newborn babies can see clearly up to 15 inches away
• All babies are color blind when they are born
• Your eyes started to develop only two weeks after you were conceived
11. Tears have different compositions
Your tears have different compositions based on whether you are yawning, or something’s irritating your eye, or you’re crying.
12. Cornea is the only tissue in the eye that doesn’t need blood
The cornea is an essential part of the vision in our eyes. Therefore, they lack blood vessels which can interfere with proper vision. Therefore, the cornea is the only living cell in the human body that is not directly connected with blood vessels. Nonetheless, the inside part is designed such that it gets nutrition from the aqueous humor which is a thick watery substance that is found between the cornea and the cornea and the lens while the outside part gets the nutrients and oxygen from the tear fluid
13. Human eyes have a blind spot
Light enters the eye by passing through the pupil then hits the retina at the back of the eye. The retina is usually covered by light sensing proteins which play a big role in controlling the amount of light that gets into our eyes. The retina then sends the imagery information to the optic nerve which transmits this information to the brain. The optic nerve is made such that it ends in the fields of the retina itself. This then creates a blind spot in our eyes. The blind spots are usually aligned symmetrically which play a role most of the time in compensating the loss of one eye field vision in the other.
14. Until about 10,000 years ago, all human beings had brown eyes.
Brown eyes are said to be old school. In fact, blue eyes are a more recent phenomenon caused by genetic mutation about 6000 years ago. This is a clear sign that human beings are still evolving. This means that if your eyes are blue, you share a common ancestor with every blue-eyed individual in the world!
15. And finally, the human eye is an incredible organ that can distinguish over 10 million different colors.
In the human eye, there are basically three colors blue, red and green. That makes up the millions of colors plausible distinguishable by the human eye. In fact, when it comes to color gray, there are about 50,000 shades of gray the human eye can distinguish. However, there are some colors that are too complex for the human eyes to comprehend called impossible colors.
Who knew our eyes could be so complex, unique and amazing? I bet after reading this you will never perceive your eyes the same way.