Are two eyes better than one?

How do we see? Learn about the science of seeing with these hands-on lessons and projects! Teach your early elementary child (K-4) about eyes and vision.

Hold one penny in each hand, using your index finger and thumb. Stick your arms straight out in front of you, with your thumbs pointing towards each other. Close one eye. Slowly bring your hands together, and try to make the pennies touch edges with each other. Let your friend try it too, and see if the same thing happens.

Try it again with the eye that was closed open and the other eye closed. You and your partner can both try several times, if you like. Try to make the coins’ edges touch with both of your eyes open. Does the same thing happen when your friend does it? You can also try using two pencils instead of pennies, and try to make the erasers touch while having one eye closed.