This book of amazing optical illusions is a good gift and good fun for people of all ages. While ostensibly a children's book, I've used the pictures here to entertain and educate groups of all ages, from young children to older adults. It is fascinating to see what different people pick up and out of the photographs, but there is always at least one picture for each group that has people protesting that the illusion is not in fact what it purports to be.

Many people are familiar with the fantastic creations of people such as Escher; while there are not actual Escher pieces, they all tap into the same element of mystery. Some of the optical illusions are very straight-forward - the image of the faces facing each other, which then becomes a vase, or the parallel lines drawn on the backdrop of pattern lines radiating out, which then gives the illusion that the lines are not parallel, are fairly well known. Other pieces, such as the portrait of Emperor Rudolf II done by Giuseppe Arcimboldo in the 1500s entirely out of fruit, or the various `spirals' constructed exclusively out of concentric, separate circles are less well known.

The optical illusions here, such as they are, are fairly simple to understand. Much of them rely on perspective distortion of the senses, pattern fuzziness, or colour ambiguities and playfulness. The side-wise house in San Francisco, for example, relies on the camera being level with the street, rather than the house; the people in photographs appearing as differently sized depends upon perspective gerrymandering.

Some of the optical illusions are quite clever; the falling bookshelves that are not in fact falling is a piece that exists in the real world; the colonnaded patio seen from above and below is more in the tradition of Escher, in that it cannot exist in the real world. This is a fun little book, that will likely give hours of amusing and thought-provoking engagement for children of all ages.