字幕表 動画を再生する 英語字幕をプリント 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 sharks than you think? Let's see! 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 per hour. - 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 it. - 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 filling. Mmmm! - 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 green than any other color. - 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. Eyelashes live for about 5 months. - 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 protein. - 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, hence the red color. - 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 has to do with how eyes reflect light. - 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 UV protection. - 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 still brown. - 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 without actually looking there. - 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 to the brain takes time. - "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. Drain-o? - 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 other particles that are in the air. 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 to stay alert. - 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 vision, for example, when they hunt. - Many insects, including bees, dragonflies, and wasps have 5 eyes: (Hey Ricky!) 2 on the sides and 3 more set in a triangle on top of their heads. They use the extra eyes to detect light and spot upcoming threats. - Some fish also have more than two eyes. With four eyes, Anableps can see above and below water at the same time! The box jellyfish go even further - these creatures have 24 eyes. They help them navigate under the water without bumping into things. Sadly the other fish tease them: “Hey 24 eyes!” ha ha ha! Hey, if you learned something new today, then give the video a like and share it with a friend! And here are some other videos I think you'll enjoy. Just click to the left or right, and stay on the Bright Side of life!