Bats and birds that look like faces. Skulls that pop up on anything white. Three donkeys with three ears be-tween 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. A fascinating, visually arresting title, which will keep the kids quiet for hours.