It is said that "seeing is believing." But what if the picture you see is hard to believe? Maybe it appears to be something else entirely. In The Great Book of Optical Illusions, Al Seckel brings together a collection of fascinating visual puzzles and enigmatic designs that make the viewer wonder: How does this work? What does it really contain? From collections of baffling shapes that defy the viewer to work out the hidden figures, to dazzling patterns that appear to change on the page, here are optical illusions found in classical art and through history to the most modern of visual tricks. There are more than 280 color and black and white illustrations in the book, from Illusionworks, the world's leading brand of illusion artworks.