An optical illusion is something that plays tricks on your vision. Optical illusions teach us how our eyes and brain work together to see. You live in a three-dimensional world, so your brain gets clues about depth, shading, lighting, and position to help you interpret what you see. But when you look at a two-dimensional image, your brain can be fooled because it doesn't get the same clues. Take a look at the optical illusions below. Can you figure them out?
Is the pencil on the right bigger than the pencil on the left? Or are they the same size?
How many fish do you see?
Is the hat taller than it is wide? Use a ruler to find out.
Is this a picture of a vase? Or two faces looking at each other? Do you see both?
Which mouth is bigger? Make your guess and then measure them to find out.