Written by Maci

Modified & Updated: 28 Apr 2024

Sherman Smith

Reviewed by Sherman Smith

eye facts
  1. You see with your brain, not with your eyes.
  2. You see things upside down, and the brain turns that image right side up.
  3. A blink lasts an average of 100-150 milliseconds.
  4. It is possible to blink a total of five times in a single second.
  5. Your eyes are the fastest muscle of your body.
  1. Our eyes capture light and send that data through the brain which registers the things we see.
  2. Eyes were believed to have first formed 550 million years ago in animals.
  3. The phrase ‘in the blink of an eye’ comes from the speed of our eyes. 
  4. The human eye can function at one hundred percent at any given time without needing rest. 
  5. A fingerprint has 40 unique characteristics, our eyes have 256. This is why retina scans are being used more for security purposes. 
  6. Oily fish, Vitamin A, and Vitamin C are believed to help your eyesight. 
  7. When your eyes water, it is most commonly caused by dry eyes. 
  8. Astigmatism refers to a defect in the eye or lens caused by a deviation from spherical curvature that results in distorted images. 
  9. Your nose gets runny when you cry as the tears drain into your nasal passages. 
  10. Tears are used to clean our eyes, yet scientists cannot figure out why we cry when we are sad.
  1. If the human eye were to be a camera, it would have a 576-megapixel lens.
  2. You are likely to blink more while you talk.
  3. The red eyes captured in photos are due to the light flash bouncing off the capillaries of your eyes. 
  4. Pirates once believed that you could improve your eyesight by wearing gold earrings. 
  5. Mayans believed that being cross-eyed was attractive and so they would make sure that their children would be crossed eyed.
Table of Contents

The human eye is one of the most useful organs found in the human body. They help us each day with our tasks such as when navigating or gathering information. 

However, we often do not appreciate our vision enough or give it much thought. Here are some interesting eye facts that will make you appreciate this amazing organ. 

The phrase “It's all fun and games until someone loses an eye” comes from Rome.

Back in Ancient Rome, bloody wrestling matches were widely popular. There were traditionally no rules regarding how a player could fight. 

However, only one rule was established sometime during this era. That rule was that there could be no eye-gouging allowed.

Albinism affects melanin production.

This condition is a congenital disorder where it is characterized by the lack of pigmentation in the skin, hair, and eyes in humans. Scientists believe that this is their cause of extra sensitivity to light and a red-eyed appearance.

The 20-20-20 rule can help your eyes.

This particular rule applies to when you work in front of a computer for hours. The rule specifies that you should look at something twenty feet away for twenty seconds every twenty minutes. 

Following this technique generally helps people prevent eye strain. It is also a great reminder for people to take a break every so often. 

You blink 4 million times a year.

Specifically, you blink a total of 4,200,000 times a year on average. That’s 12,000 times a day!

Blue-eyed people are related.

It is believed that every single person with blue eyes shares a common ancestor with every other blue-eyed person in the world. 

Eye Facts

Eyes can heal quickly.

If you have a minor corneal scratch, it can be healed within 48 hours with proper care. 

Diabetes can lead to blindness.

Diabetic retinopathy is an eye condition that causes vision loss and blindness. This can occur to people who have diabetes. 

This is also the number one leading cause of blindness in adults from the United Kingdom.

Tying a tie too tight can cause glaucoma.

According to research, if you tie a tie too tightly, it can increase the risk of glaucoma in men. Too tight of a knot can increase the pressure in the eye which is the leading risk of obtaining this disease. 

Eye tests can detect health conditions.

Doctors can detect health conditions such as diabetes and high blood pressure during a sight test. The doctor can detect this by observing the blood vessels in your retina. 

Our retina is said to be a good predictor of the health of blood vessels throughout our body’s system.

Your children can have blue eyes even if it does not run in your family.

Recessive traits such as eye color can still appear in later generations despite the lack of presence in previous generations. 

Brown is the most common eye color.

Approximately 79% of the world’s population has been recorded to have brown eyes. Second to this, the next most common eye color is blue at 8-10%, and the following is amber or hazel eyes at 5%.

Some rare eye colors include red, violet, and grey.

Our two eyes allow us to have depth perception.

Scientists found that by having two eyeballs, we constantly compare two images at once. These images allow us to determine how far away an object is from us. 

Eye facts
Photo by Alexandru Zdrobău

The mass of an average eyeball is light.

One eyeball weighs approximately 28 grams. 

Our eye muscles are active.

The muscles found around the eyes are the most actively used in the body. 

Smoking affects your vision.

Smoking can reduce your ability to properly see objects in the dark. This is because smoking has a derogatory effect because it can lead to the deterioration of your night vision. 

Our eyes have blind spots.

This is located where the optic nerve passes through the retina. This is where our brains use the information from the other eyeball to fill the gap. 

In this location, there are no photoreceptors, hence there is no image detection in this area.

We have hollow eye sockets.

Our eyes are positioned inside a hollow eye socket to protect it from damage. The socket is a bony cup that surrounds the eye. 

This socket also contains all the muscles that allow you to move your eyes in multiple directions. This area also includes tear glands, blood vessels, and cranial nerves.

eye socket, skeleton, eye facts
Photo by Mathew Schwartz

Vision impairment is curable.

About 80% of the world’s vision problems can be solved with proper treatments.

Our eyes have a lot of parts.

Research has discovered that the human eye contains over two million working parts for it to function. 

Eye transplants are not possible at this time.

Due to the amount of optic nerves located in our eyes, it is currently impossible to perform an eye transplant due to the sensitive nerves. Perhaps with better medical technology in the future, this could be possible. 

One eye is always stronger than the other.

This is also referred to as anisometropia. This prompts our brains to favor one eye over the other because it sends better images and information.

Owls can't move their eyeballs.

This explains the notable way they turn their heads to better see things. They are also capable of turning their heads all the way around. 

Eye muscles are incredibly strong.

The muscles found in the human eyes are about 100 times stronger than they need to be to perform their functions. 

We can only see a total of 3 colors.

According to research, scientists have found that we humans can only view the color red, green, and blue. Any other colors we see are merely a mixture of two of these colors or more. 

A dragonfly’s eye has multiple lenses.

To be exact, a dragonfly has 30,000 lenses in its eyes. This greatly assists them in motion detection that makes them very difficult predators to kill. 

Unlike human eyes, chameleon eyes are independent.

This greatly explains why chameleons are capable of looking at two separate directions at the same time on command. The chameleon uses this monocular vision to hunt its prey. 

When it locks onto a prey, both eyes focus to that point.

chameleon, eye facts
Photo by Ante Hamersmit

Shark eyes are used for human surgery.

To be more precise, the cornea of the shark is used during human surgery. This is because a shark’s cornea has the most similar cornea to humans. 

Additionally, sharks can see in the dark due to an eye tissue called the tapetum lucidum. This is also the same material that allows the shark’s eyes to glow in the dark. 

Cosmetics is one of the most common cause of eye injury.

Using eye makeup, especially mascara and eyeliner, is said to be one of the most common eye injuries to take place among women. 

A newborn baby cannot produce tears.

This is because newborn babies have not produced tear glands yet. Commonly they develop this between the age of two weeks to two months old. 

There are also some cases in which babies have clogged tear ducts which prevent tears from being released.

Contact lenses cannot be lost in your eyes.

This is not possible mainly due to the structure of the human eye. No item can slide into the back of the eye because of the muscles that protect the eyeball. 

If you do “lose” your contact lenses, simply apply contact lens solutions and massage your eyeball gently while keeping your eyes closed.

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