Optical illusions are images or pictures that we perceive differently than they really are. Put another way, optical illusions occur when our eyes send information to our brains that tricks us into perceiving something that does not match reality. Scientists believe optical illusions are possible because our brains are so good at recognizing patterns and “seeing" familiar objects. Our brains work quickly to make a “whole" image from separate pieces. This website shows 10 different optical illusions and how they work.