Grade 5-10-- With over 60 optical illusions and entertainments based on them, this book will delight those with an interest in mystifying friends or in the science of psychology or optics. Most of the illusions can be experienced directly from the illustrations in the book or reconstructed on paper with ruler and compass. Moving optical illusions can also be constructed, most using a pencil as a turntable. The construction directions and diagrams are clear. Only a few constructions qualify as "toys," and these are easily made with inexpensive household materials. A book that is sure to provide readers with many hours of fun.