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Would you like to watch your face disappear? Without actually being removed from your body of course? This simple experiment reminds us about how the eye, or rather, two eyes work together and, as it were, stich together two images to create a coherent single image that we perceive.

What You Will Need:

• A hand-held mirror
• A white wall, or other white surface (posterboard or a screen will do)
• Somebody to be your Cheshire Cat!

What to Do:

1. Sit so that the white surface of the wall is on your right. Get that friend of yours to sit a couple of feet away, facing you. Now, hold the bottom of the mirror with your left hand, putting the mirror against your nose so that the reflecting surface of the mirror is pointing sideways, facing the white surface.
2. While you keep the mirror’s edge against your nose, rotate the mirror so that your right eye sees only the reflection of the white wall. Your left eye should be staring at your friend.
3. Now, move your right hand in front of the white wall, as though you were erasing a blackboard.
4. Watch as part of your friend’s face seems to disappear!
5. If you have trouble seeing your friend’s face vanish, you may have one eye that is stronger than the other. Try switching positions with your partner, using the other eye to look in the mirror facing the wall. You might have to try it a couple of times to get it to work — don’t give up!

Why It Works:

So here you are, living your life as though both of your eyes see the same thing. Surprise! Each actually sends a separate picture to your brain, which analyzes the images, and combines them to form one image. In this experiment, your brain is trying to make sense of the signals you send by selecting bits of information from each eye’s view.

Because your brain is so sensitive to changes and movement, it pays more attention to the moving hand than the sitting person. Isn’t it mysterious how part of the face remains in view? Kind of like the Cheshire Cat from Alice in Wonderland. Talk about a brain teaser!