Preface Part of the fun of this book will involve being tricked, fooled, and misled. Being fooled has nothing to do with how smart you are, how cultured you are, how artistic you are or how old. You will be tricked. In fact, many of the illusions are so powerful you will doubt the written description. Others are so convincing, you will not know what the illusion is until you read the caption. This volume is by far the most comprehensive collection of illusions ever published. A good number come from recent work in vision and perception laboratories and others come from a variety of modern artists who have deliberately incorporated an illusion into a drawing, photograph, or sculpture. There are also quite a few illusions that have been created specially for this book.

I have tried to provide a variety of different perceptual experiences. Many of the illusions in this book appear here for the first time in print. Of course, you will find the familiar classics here too. The chapter "Your Mind's Eye" puts the illusions into a framework of modern understanding. At the back of the book you will find a chapter "What's Going On?" that provides brief scientific explanations of our best guesses for why these effects occur and how they are consistent with the processes that mediate normal perception. There is also a glossary of technical terms that are used throughout the text, a category index so you can compare similar examples of the same type of illusion as well as suggestions for further reading.