For sighted people, the eyes are one of the most important organs of the human body. These slimy Ping-Pong balls are largely responsible for helping you understand and interpret the world around you—using more than two million moving parts and eye muscles that move more than a hundred thousand times a day! And thanks to your eyes, you have the ability to appreciate the colors of a rainbow, enjoy a smile from someone you love, or even watch out for dog poop on the sidewalk before you step in it. Your eyes are literally always looking out for you. Thanks, eyes!
Let’s meet the different parts of the eye and learn a little bit about how they all work together to help you see!
Hey all! Iris here. I’m the beautiful colored part of your eye, and believe it or not, I am basically all muscle! I’m also a total control freak! It’s my very important job to pick and choose the exact amount of light that’s allowed to enter the lens through ol’ Pupil. It’s easy—I just grow and shrink, and light bends to my will. And not to toot my own horn (okay, I’m totally tootin’ here!), but it’s because of me that you can see in different amounts of light! If it’s sunny outside, I grow extra big and put the brakes on the amount of light I allow in. And when you go to the bathroom in the middle of the night, I get real small, opening the gates up wide to let whatever light is out there come in. In other words, eye am super loyal and there for you day or night!
Um . . . hello, my name is Cornea and I am here to protect and serve. You probably don’t even notice I’m here. I’m just a thick, clear, protective layer guarding your eye from all the junk that tries to get in there. If you protect me by not sticking garbage in your eye, you can rest assured that I will always protect you. And by you, I mean your eyeball, and that’s pretty much it.
Hi, hi! Pupil here! Some people call me “PeeOOP” and some call me “Poopil,” but I prefer to be called by my given name, Pupil. I am that little black dot in the middle of your eye. Can you even imagine what your eye would look like without me?! Try it right now—IMAGINE IT! NOW STOP IMAGINING IT! Creepy, right? My job is to let the light in to hit the back part of your eye, called Retina. (Shout-out to Retinaaaal) Retina and I work together like a projector and a movie screen. Like a projector, the light that comes through me is focused by Lens (you’ll meet Lens next), and then it’s projected onto Retina just like a movie screen! Okay, Lens, you’re up!
Hello, my name is Lens, and like Pupil said, it’s my job to keep things focused. And by “things,” I mean light. I sit back here behind Iris, WHO DOESN’T EVEN KNOW I EXIST BECAUSE I’M SO CLEAR AND COLORLESS, and focus light rays on the back of your eyeball, AKA (also known as) Retina. Retina, take it away!
They call me Retina, because that’s what I am. For me, every day is Opposite Day, and here’s why: Because your eyeball is curved, whatever you look at hits me upside down. Even so, I take this information and send it to your brain via Optic Nerve. Thankfully, your brain has the power to flip it around and make it right-side up again. Hey, Optic Nerve! Introduce yourself!
Nice to meet you! My name is Optic Nerve and I pretty much just hang out here at the back of your eye and send info on what you see to your brain. No biggie, I’m just the messenger. Except, of course, YOU WOULD NEVER BE ABLE TO SEE WITHOUT ME!
The word “pupil” means “little person.” Could this be because tiny versions of ourselves are reflected in other people’s pupils?!
Due to our lack of thick fur everywhere, our furry eyebrows are much more noticeable than other animals’. But just imagine if your family pet had eyebrows as bushy as yours. A fish with eyebrows?! No laughing!!
There are about 250 hairs in a human eyebrow, but grownups who have never plucked them could have more than one thousand hairs!
Eyelids (AKA eyelash holders) are the official blinkers of the human face. They not only help to keep our eyeballs slimy with mucus and oils—and help to refocus our eyes when we blink—but they also work like tiny windshield wipers to clear away all the dust and other microscopic junk that shouldn’t be there.
While your nose and ears continue to grow, grow, grow throughout your lifetime, the eyes that you were born with stay the same: about the size of a Ping-Pong ball! (Okay, fine. They grow a few measly millimeters in the first two years of your life, but after that, they pretty much stay the same.)
People with blue eyes all share a common ancestor!
Some people have two or even three rows of eyelashes! Actress Elizabeth Taylor was one of these people.
People with heterochromia have two different colored eyes or eyes that have more than one color. Just another reason to always look people in the irises!
When you get snotty while crying, it’s a result of tears draining into the back of your nose and mixing with snot.
Because of blinking, our eyes are closed for about 10 percent of the time we’re awake!
As many as 20 percent of people, from babies to adults, can sleep with their eyes open!
Astronauts cannot cry in space—at least not the usual way. Without gravity, tears don’t fall downward out of the eye. Instead, they form into little balls of liquid that hang out in the eye and cause a stinging sensation. And according to astronaut Chris Hadfield, space tears can really sting!
Use your eyeballs to spot the true wow among the totally made-up whats?!:
If unprotected, your eyes can get sunburned.
If you sneeze with your eyes open, your eyeballs will pop out of your face.
One out of ten humans suffer from “ticklish eyes.”
ANSWERS
wow
what?!
what?!
The most common eye color in the world is . . .
Blue
Hazel
Brown
Mismatched colors
Eye transplants are . . .
Fun
A pain in the eye
Dangerous but worth it
Currently impossible
ANSWERS
(C) Brown. Over half of the people in the world have brown eyes.
(D) Currently impossible. Surgeons are unable to rewire the one million fibers that make up the optic nerve, which connects the eye to the brain. But, it is possible to get a cornea transplant.