Bats and birds that look like faces, skulls that pop up on anything white, three donkeys with three ears between them, and, walls that disappear - relax, they're only optical illusions. Examine thousand-year-old drawings, find out about closure, perspective, "the Rubin vase" and how these tools can untangle the tricks found in this volume. This book is a fascinating, visually arresting title, which will keep the kids quiet for hours.