Name: 30 Little-Known Facts About Your Second Most Complex Organ
Uploaded: 2020-05-10T18:25:50.000Z
Duration: 8 min 55 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

It's your second most complex organ after the brain, and it's responsible for 80%

of everything you learn. Yep, I'm talking about your spleen! No wait. It's your EYES!

Yeah. How many colors can they distinguish? And why do you have way more in common with

But first I have this: Remember the TV show I Love Lucy? Well, what did Lucy's husband

Ricky Ricardo say when he met a guy on the street with five eyes? Give up? “Ay, ay,

ay, ay, ay…” Okay maybe you never saw the show. Let's move on.

- Your eye has over 2 million working parts! One million nerve fibers connect it to the

brain! As all the pieces work together, they process around 36,000 bits of information

- The eyes see things upside down. The brain then interprets this information and flips

images for us. That's because the cornea is curved, and light bends when it goes through

- Your eyeball is around the same size as a gumball you can get from a grocery store

gumball machine. The lens in the eye is the size of an M&M candy. It also has protein

- The human eye can distinguish 10 million colors. All of them are combinations of three

basic colors: red, green, and blue. Out of those 10 million, people see more shades of

- Iris scans are way more individual than fingerprints. Compare these figures: your

fingerprint has 40 unique features, and your iris has 256! That's why biometric iris scans

are the present and future of security checks.

- If you put all the eyelashes you'll shed during your life in one line, it will be 98

feet long. It differs from person to person, but you lose on average 1 to 5 lashes a day.

- The first creatures to have eyes were single-cell organisms some 550 million years ago. I wasn't

around then. Their eyes didn't look anything like ours: they were patches of photoreceptor

- Do you often get red eyes in photos? Blame your blood vessels. When the light from the

camera flash gets reflected, it lights up the blood vessels at the back of your eyes,

- Your eye size and shape affect your vision. People with larger eyes are often nearsighted.

And those who have eyes a bit shorter than average are likely to be far-sighted. This

- Shark cornea is almost 100% the same as the human one. In the future, it might allow

scientists to use shark cornea proteins to create biomaterials for making cornea substitutes

for people. Yes, there's something fishy going on here.

- You can sunburn your eyes. Symptoms resemble those of skin sunburn plus blurry vision.

You can't put sunscreen on your eyes, (ouch) but remember to wear quality sunglasses for

- Everyone, even a person with perfect vision, has a blind spot. It's on top of where the

optic nerve meets the retina. You aren't likely to notice it unless you experiment on purpose.

Your brain fills in the missing data for you.

- 10, 000 years ago, everybody had just one eye color – brown. The first blue-eyed person

was born as a result of a genetic mutation. If you have blue eyes, that was your ancestor.

You share him or her with 10% of the world's population. The most popular eye color is

- Eye muscles are the fastest of them all. They enable your eyes to move at a speed of

500 degrees per second. They can also focus on 50 different objects in just a second.

Many of the moves your eyes make are automatic. That's why you can see something on the periphery

- You blink around 15-20 times a minute, 20,000 to 30,000 times a day, and at least 7 million

times a year. Each blink lasts just a moment. And still, when you sum up all of them, it's

1.5 hours daily. You blink more when you're talking and less when you're reading a book

or something from a computer screen. That's why in the second case, your eyes get tired

faster. Blinking helps your eyes stay clean and healthy.

- The resolution of the human eye is 576 megapixels. But before you throw away your expensive camera

(which is not nearly as good!), hear me out! The eyes only have that many color receptors

in a tiny spot in the center. You need to move them a lot to get the full picture.

- You never sneeze with your eyes open. It IS technically possible. But an absolute majority

of people have an autonomic reflex to shut their eyelids when they're about to sneeze.

That's how your body protects your eyes from all those nasty things that can jump out of

your nose. Is it pretty? No it's not (snot).

- An adult with healthy vision can detect a candle flame from as far away as 1.7 miles!

This distance could probably be even bigger if the Earth's surface wasn't curvy and there

weren't other sources of light and natural obstructions.

- New-born babies are color-blind. And even though the little ones make a lot of crying

sounds, they never really shed tears. The tear ducts only start properly functioning

when babies are somewhere between 4 and 13 weeks old. But yeah, they cry from day one.

- It also takes some time for babies to learn to see! In the womb, their eyes get ready

to distinguish shapes, some colors, and light. But right after birth, babies can only focus

on something that's very close to them, like a parent's face when they hold them. Learning

to focus properly, move eyes, and interpret visual information that goes from the eyes

- "20/20" has nothing to do with perfect vision. It only means you can see as well as other

people from a distance of 20 feet. Those with the sharpest eye have 20/10 vision. It means

they can see from 20 feet what the average person would only spot from 10 feet.

- There is a gel-like fluid in your eyes. It makes up 80% of the eye and floats between

the lens and the retina. It helps your eye stay in shape and protects the retina. When

you're young, the fluid is as thick as "Jell-O." As you get older, it becomes more liquid.

- Your eyebrows and eyelashes have important protective functions. The eyebrows stop sweat

and other fluids from getting into your eyes. Eyelashes don't let in moisture, dust, sand,

And now, do you know how long eyelashes help camels survive in the desert? Nope, they don't

wink at travelers asking for water. The long eyelashes keep sand out of their eyes.

And since we've moved on to animals, some of them have pretty cool eyes, too!

- Ostriches have eyes that are as big as billiard balls. Each eye is also larger than the bird's

brain. No wonder they're the champions of the land animal kingdom when it comes to the

eye size. Huge eyes and a small brain might be the reason why ostriches run in circles

when they see predators – not the smartest tactics, right?

- The colossal squid has the largest eyes in the world - each the size of a soccer ball!

- Hamsters blink for the same reason as humans – to get rid of dust and other unwanted

particles. But they only blink one eye at a time and keep looking around with the other

- Geckos can distinguish colors 350 times better than humans. They can even see colors

at night and notice ultraviolet and green light. Since they don't have eyelids and can't

blink, they lick their eyes to clean them and keep them moist. Boy that's a tongue.

- Chameleons' eyes are cool and unique: these animals have 360-degree vision. Their eyes

can also function independently. It means they can switch from binocular to monocular