Vision, more than any other sense, dominates our mental life. Our visual experience is so rich and so detailed, that we can hardly distinguish that experience from the world itself. Even when we just think about the world and don't look at it directly, we can't help but imagine what it looks like. We think of 'seeing' as being an exclusively conscious activity - we direct our eyes, we choose what we look at, we register what we are seeing. The research described in this book has radically altered this attitude towards vision. The odyssey begins and ends with the story of a young woman (here called 'Dee') apparently blind to the shapes of things in her visual world due to a devastating brain accident. As their investigations unfolded, Milner and Goodale found that Dee wasn't in fact 'form-blind' at all - she could register the shapes of objects unconsciously, though she didn't at first realise it. Taking us on a journey into the unconscious brain, the two scientists who made this discovery tell the amazing story of their work, and the surprising conclusions about the normal brain's hidden capacities they were forced to reach. Written to be accessible to students and popular science readers, this book is a fascinating illustration of how the study of a damaged brain can reveal much about the human condition.