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Eye muscles are fast -

The six muscles in each of your eyes move faster than any other muscles in your body. Known as the extra ocular muscles, they're located around the eyeball and inside the eye socket.

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Eyes do grow -

You've probably heard that eyes don't grow. But in reality, your eyes grow considerably in your first two years of life. They reach full size by adulthood.

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The cone cells help you see -

Your retina has seven million cone cells that help you see colors. Then you also have 100 million rod cells to help you see​ in the dark.

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The first eyes appeared over 550 million years ago -

Primitive life-forms didn’t have eyeballs like humans and many animals do today. Instead, single-celled organisms had patches of photoreceptor proteins that could detect light.

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Thank your brain -

Your cone cells detect either red, green, or blue. Your brain combines them to show you all the other remaining colors of the rainbow.

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500 shades of gray -

Rods don't help with color vision, which is why at night we see everything in a gray scale. They also contain a pigment that's sensitive to green light.

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Color-blindness -

Men are more likely than women to be color-blind. This happens when one of the three kinds of cone cells that detect color is missing.

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Smoke gets in your eyes -

Smoking and secondhand smoke increase your risk for age-related vision loss. Also, cataracts tend to develop faster in people who smoke.

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Newborns have blurry vision -

Newborns have blurry vision for the first four months, which develops over time. It also takes the same amount of time for a baby to fully see colors and distant objects.

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Eyes are well protected -

Thanks to eyebrows and eyelashes, the eyes are well protected. Eyebrows prevent sweat from reaching your eyes, while eyelashes help keep dirt out of them.

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The size of an eye -

Our eyes are about one inch (2.54 cm) across and weigh about 0.25 ounce (seven grams). There's no significant difference between sexes and age groups in terms of eye size.

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A new perspective -

When the lenses in your eyes focus an image on your retina, it’s upside down and backward. What happens is that your brain actually reorients and right-sizes the image for you.

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Two eyes help with depth perception -

Having two eyes helps with depth perception. Your brain calculates distances by comparing the distinct images from each eye. People who lose sight in one eye have a declined ability to track moving objects, judge distances, and perceive depth.

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The world's most common eye color is brown -

It’s estimated that 70-79% of people have brown eyes, while 8-10% have blue eyes, and only about 2% have green. Brown eyes are more common in warmer climates because excess melanin protects the eyes from sunlight.

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Blue and green eyes can jump generations -

Even if no one in the past few generations of your family had blue or green eyes, these recessive traits can still appear in later generations. Also, research shows that people with blue eyes have a single, common ancestor from 6,000-10,000 years ago.

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Green eyes are very rare -

With only 2% of the world's population having green eyes, it's the rarest eye color. Just like blue eyes, green eyes are a genetic mutation that results from low levels of melanin.

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Seeing with your mind -

The reason why you can see is that your eyes capture light like a camera. It then sends the data back to your brain, where the pictures 'develop.'

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There are no blood vessels in the cornea -

The cornea is the only tissue in the human body that doesn't contain blood vessels. In fact, there's a serious eye condition called interstitial keratitis that causes the growth of blood vessels in the cornea. It must be treated immediately.

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Our eyes close automatically to protect us from danger -

If our brains detect something dangerous coming toward us, we automatically close our eyes to protect them from harm.

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Our eyes have blind spots where the optic nerve crosses the retina -

To make up for these blind spot gaps, our brain uses stimuli from our other eye to figure out what we’re missing.

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People can have different eye colors -

Known as heterochromia, it's when a person has differently colored eyes or eyes that have more than one color. It's caused by genes passed down from your parents or by something that happened when your eyes were forming.

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Eyes are complex -

Eyes are the second most complex organs after the brain. Eyeballs have over two million working parts, and more than one million nerve fibers that connect each one to the brain.

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It's possible to sneeze with your eyes open -

While it's possible, it's not recommended to do so. By automatically shutting the eyelids when a sneeze occurs, more bacteria can be prevented from entering and aggravating the eyes.

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Ommatophobia is a fear of the eyes -

Ommetaphobia describes an extreme fear of eyes. And like other phobias, this type of fear can be strong enough to interfere with your daily life and social activities.

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Eyes heal quickly -

With proper care, it takes only about 48 hours to repair a minor corneal scratch. Fast healing happens because the cells on the outside of the eye are living cells, unlike the dead cells that make up your skin.

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We blink a lot -

On average, you will blink approximately 4.2 million times in a single year. That's about 12,000 times per day!

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An eye exam can detect different health conditions -

During an eye exam, health conditions like diabetes can be detected. Also, if the optometrist takes a retinal photograph, signs of high blood pressure can be seen in red areas of hemorrhaging in the eyes.

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No tears -

Tears are rare at the beginning and the end of life. Newborns can’t produce tears for about six weeks. Also, the older you get, the fewer tears you produce.

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The resolution of the human eye is 576 megapixels -

If one of our eyes was a digital camera, it would have 576 megapixels. In comparison, some of the best cameras in the world have only around 50 megapixels.

Sources: (Cleveland Clinic) (ADV Vision) 

See also: Tips for eye health and maintaining good eyesight  

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