Now you see it; now you don't! Magicians sometimes make things "appear" or "disappear" by creating optical illusions (images that trick your eyes). To understand how an optical illusion works, it is important to know how your eyes and brain work together to get information.

You see things because they reflect light. The light travels through the outer parts of the eye to nerve cells in the retina. The nerve cells send the information they have to the brain. Your brain's job is to figure out what you are seeing. That's where the magician comes in.