Six strings on each eye
Your eyeball sits in a bony cup in your skull called the eye socket. Six thin muscles hook onto the eyeball and steer it.
Four of them pull straight: one up, one down, one toward your nose and one toward your ear.
The other two wrap around at a slant, so your eye can roll and tilt a little. One of them even runs through a tiny loop of tough tissue, like a rope through a pulley.
Fast and busy
Your eye muscles are some of the busiest muscles in your body. They move your eyes all day long.
When you look around or read, your eyes make quick little jumps, about three every second. Scientists call them saccades (sa-KADS). They're some of the fastest moves your body can make.
You don't notice the jumps, because your brain smooths the picture out for you.
Try it: ask a friend to read a few lines of a book while you watch their eyes. You'll see little hops, not one smooth slide.
Two eyes, one team
Your brain sends matching messages to both eyes, so they move together and look at the same thing.
Try it: hold one finger out at arm's length. Watch it as you slowly bring it to your nose. Feel your eyes cross? Both eyes turned in as a team.
Now look at something far away. Your eye muscles relax, and your eyes point straight ahead again.
The blinking muscles
Blinking uses the ring muscle around your eye, which closes your eyelid, and a lifter muscle inside your upper eyelid, which opens it again.
You blink about 15 to 20 times a minute, mostly without thinking about it.
Every blink spreads a thin layer of tears across your eye to keep it wet and clean. A blink is over in a flash.