Hole in Your Hand
Description: Students will create an optical illusion with an every-day object
Purpose: To show that each eye sees a slightly different view, and that the brain puts the two views together to form one image
Length of Activity: 15 minutes
- 1 cardboard tube (paper towel, toilet paper roll) OR
- Roll one sheet of paper into a tube
1. Give students a card board tube or instruct students to roll up a piece of paper into a tube.
2. Have students hold their tubes in their left hands and place in front of their left eye.
3. Tell students to look through the tube like it was a telescope but keep both eyes open. Choose an object in the distance to look at.
4. Students then should hold their right hands in front of their right eye, with palm facing them, about 2 inches from their face or just beyond their noses.
5. Students should place the edge of their hands next to or touching the tube.
What’s Going On?
Do you see a hole in your hand? When you look through the tube and see a hole in your hand, you are seeing an optical illusion. The tube allows you to look into the distance with your left eye and to see your hand with your right eye. Your brain took what your left eye saw and put it together with what the right eye saw, forming one image. That image makes it seem like there's a hole in your hand.