Today’s Wonder of the Day was inspired by mari. mari Wonders, “Why do we blink?” Thanks for WONDERing with us, mari!
Would you believe your eyelids are like windshield wipers for your eyes? It's true! The eyelids are simply folds of skin controlled by speedy muscles that can open and close your eyes so quickly that it doesn't affect or disrupt your vision.
Blinking protects your eyes from drying out by irrigating or moisturizing them. Even when you're not crying, your tear ducts are still hard at work producing fluid. When you blink, your eyelids use suction to pull fluid from your tear ducts and spread it over your eyeballs.
If you've ever had something in your eyes, you know it can be a very painful and irritating experience. Blinking also helps protect your eyes from foreign objects such as dust, dirt and sand. How? Your eyelashes, of course!
Your eyelashes aren't just for looks. They serve an important function: eyelashes work a bit like a feather duster, collecting tiny particles before they can reach or attach to your eyeballs. If you find yourself in a strong wind, your body's natural reflex is to lower your eyelids and blink more rapidly. This protects your eyes from blowing particles and reduces the exposed part of the eyeball, a bit like lowering the shades on a window.
Have you ever seen a camel up close? If so, you may have noticed that camels have some of the loveliest lashes in the animal kingdom. That's no accident! Camels have extremely long, curly eyelashes to protect their eyes from sandstorms in their desert habitats.
While blinking can be triggered by dry eyes and foreign objects, scientists believe it is mostly controlled by a blinking center made up of nerve cells in the brain. The average adult blinks 10-20 times per minute. Babies blink far less than adults, only one or two times per minute. No one knows exactly why babies blink so infrequently, but there are several theories.
Some researchers believe it is because an infant's eye opening is so much smaller than an adult's. This smaller space requires less lubrication. Others believe it is because babies sleep much more than adults and tired eyes blink more. No matter what the reason behind baby blinking, the blink rate increases throughout childhood and, by the time children reach their teens, their blink rate is usually the same as an adult.
Most people blink every 2-10 seconds. In one study, subjects blinked about 10 times per minute. When the subjects had their eyes focused on an object (such as reading, sewing or staring at a computer screen), their blink rate decreased to about 3-4 times per minute. This is why many people experience dry, tired eyes when reading or doing computer work.