This book celebrates binocular vision by presenting illustrations that require two eyes to see the effects of cooperation and competition between them. Pictures are flat but by printing them in different colours and viewing them through similarly coloured filters (included with the hardcover book) they are brought to life either in stereoscopic depth or in rivalry with one another. They are called anaglyphs and all those in the book display the ways in which the eyes interact. Thus, the reader is an integral element in the book and not all readers will see the same things. The history, science and art of binocular vision can be experienced in ways that are not usually available to us and with images made specifically for this book. The study of vision with two eyes was transformed by the invention of stereoscopes in the early 19th century. Anaglyphs are simple forms of stereoscopes that have three possible outcomes from viewing them – with each eye alone to see the monocular images, with both eyes to see them in stereoscopic depth or rivalry, or without the red/cyan glasses where they can have an appeal independent of the binocularity they encompass. Through the binocular pictures and the words that accompany them there will be an appreciation of just how remarkable the processes are that yield binocular singleness and depth. Moreover, the opportunities for expressing these processes are explored with many examples of truly binocular art.