How We See

Your eyes are like living cameras. They capture light and focus it to make sharp images. But your eyes alone do not see. They send signals to your brain, and your brain creates the pictures you see. Your eyes and brain work together incredibly fast to help you see the world.

How Light Enters the Eye

Light enters your eye through the pupil, the dark circle in the center. The colored iris around the pupil gets bigger or smaller to control how much light comes in. Behind the pupil, a clear lens focuses the light onto the retina at the back of the eye. The lens changes shape to focus on things near and far.

From Light to Brain Signals

The retina is covered with millions of special cells called rods and cones. Rods help you see in dim light. Cones detect color. When light hits these cells, they create electrical signals. The signals travel along the optic nerve to your brain. Your brain flips the image right side up and figures out what you are seeing.

Fun Facts

• Your retina actually receives images upside down. Your brain flips them right side up.
• Human eyes can distinguish about 10 million different colors.
• Your eyes blink about 15 to 20 times per minute to keep them clean and moist.

Did You Know?

Some animals see very differently from humans. Mantis shrimp have 16 types of color-detecting cells compared to our three. Eagles can see things clearly from a mile away that we would need binoculars to see!