Pocket Puzzlers: Optical Illusions

Seeing shouldn't always be believing... It all depends on how you look at it--every one of these drawings has a built-in "deception." For example, in this picture how many cubes are there: 7 or 8? Count again: if you're focusing on the black tops, you'll come up with 8, but if your eye is on the white bottoms, you'll find 7 cubes. Some images show two things in one, others confound your perception so you won't be able to judge size, and still more seem to sparkle and pulse. You won't be able to take your eyes off them! 96 pages, 86 b/w illus., 4 x 5.