Which is the most precious of our senses? As the faces of his nearest and dearest began to fade and disappear into the blurred haze of sight loss, Derek Hull reflected on the possibility of a life without vision. Inspired by a schoolboy's essay and an 18th century mathematician, he draws on his professional and personal experiences to regale us with the anecdotes from his rewarding, colourful life which illuminate his struggle to seek fulfilment within the confines of his changing world. Although a personal story, there is a wider focus too; it explores the difficulties of losing sight and shines a spotlight on the challenges faced by those who live in the shadow of sight impairment. His story is a celebration of the intricacies and beauty of the world, the joy of friendship and the intriguing wonder of science and it reminds us, that blindness needn't mean less colour. Royalties from the sale of this book will be donated to various eye charities.