13 Crazy Facts About the Human Eye

The human body can do amazing things. Nothing can quite compare with the eyes though. Each eyeball is made up of over 2 million working parts. That’s right… 2 million. That means that the eyes are always busy doing something awesome. If you think you know your eyes just because you’ve had them your entire life, think again. Prepare to be amazed by what your eyes are capable of.

13 Crazy Facts About Your Eyes

  1. There is a blind spot in your vision. This is because of a hole in the retina where the optic nerve attaches. You don’t notice it because your eyes work together to mend the blind spot. Each eye makes up for the missing information in the other eye.
  1. Blue eyes are actually a genetic mutation. Everyone had brown eyes until about 6,000 years ago. So, if you have blue eyes, then you are technically genetically related to every other blue-eyed person on earth. Also, it is possible to be born with blue eyes, even if you don’t have blue-eyed relatives on either side for several generations.
  1. What about eyelashes and eyebrows? Well, they actually have a purpose other than a canvas for makeup. The eyebrows are there to keep sweat from dripping in the eye and the eyelashes are designed to keep dirt and dust from getting into the eyes. Each eyelash has a life span of about 5 months.
  1. Newborn babies have some interesting eyes. Their new eyes, which started to develop only 2 weeks after conception, are colorblind. They can only see clearly up to 15 inches away, which is the distance from a nursing mother’s face to her baby’s face. Newborn eyes aren’t capable of producing tears until about 4 weeks of age.


  1. Speaking of brand new eyes, your eyes are the same size for your entire life. They won’t grow, unlike your ears and nose. The average eye is about 1 inch across and weighs just under one ounce.
  1. Tears are made of different materials for different reasons. Tears made for crying, yawning, or to get an eye irritant out all have a different make-up. And, tears aren’t just water. They’re made up of a fatty outer layer and a mucous inner layer, with a small layer of water in between.
  1. Your eyes don’t actually see – your brain does. The images reported to your brain by your eyes are backwards and upside down. Each half of the brain receives one half of the image. Your brain has to compose the image into what you normally see. Also, some vision impairments are the result of a flaw in the vision cortex of the brain, not in the eye itself.
  1. Your eyes only have three color receptors. Your retinas can detect red, yellow and blue. However, the red receptor really only picks up on yellow-green, and the green receptor sees blue-green. Your brain has to combine these signals to create the color red in an image.
  1. Blinking is a strange phenomenon. Each blink lasts about one-tenth of a second. It’s possible to blink 5 times in one second. The average person blinks about 17 times per minute. That equates to blinking 14,280 times per day, and more than 5 million times per year. And finally, you actually blink more when you are talking to someone than when you are reading.
  1. Think 20/20 means that your vision is absolutely perfect? Think again. All it means is that you can see 20 feet in front of you as well as the average person. The higher the bottom number, the better. For example, 20/15 means that the person can see things from 20 feet what an average person can see from 15. 20/200 can only see things like letters on a stop sign, and is considered to be legally blind.
  1. The muscles around the eye are the most active muscles in the entire body. Your eye constantly makes little jerking movements called microsaccades. These small movements keep objects in your vision from fading, because according to Troxler’s Effect, static objects in your line of sight will fade from your vision if you stare at them for a longer period of time.
  1. Eyes have interesting physical qualities. The iris, or the colored part of the eye, has 256 unique characteristics. A fingerprint has only 40, which is why many security programs now use retinal scanning. The cornea is the only tissue in the entire body that doesn’t have blood. The choroid, which is located behind the retina and is rich in blood vessels, is the reason why the eyes appear red in some photographs. The light reflects off of the blood vessels, giving the “red eye.”
  1. Vision problems are quite common. 39 million people are blind, and nearly 6 times that number have vision problems of some kind. Vision problems can be the problem of a misshapen eyeball – nearsighted people have longer eyeballs, whereas farsighted people have shorter eyeballs. Most importantly, 80% of vision problems are preventable or even curable. Talk to the specialists at Advanced Eye Medical for more information.