The bestselling author of "The Man Who Mistook His Wife For a Hat" describes how we experience the visual world. In "Musicophilia", Oliver Sacks explored music and the brain; now, in "The Mind's Eye", he writes about the myriad ways in which we experience the visual world: how we see in three dimensions; how we recognize individual faces or places; how we use language to communicate verbally; how we translate marks on paper into words and paragraphs, even how we represent the world internally when our eyes are closed. Alongside remarkable stories of people who have lost these abilities but adapted with courage, resilience and ingenuity, there is an added, personal element: one day in late 2005, Sacks became aware of a dazzling, flashing light in one part of his visual field; it was not the familiar migraine aura he had experienced since childhood, and just two days later a malignant tumor in one eye was diagnosed. In subsequent journal entries - some of which are included in "The Mind's Eye" - he chronicled the experience of living with cancer, recording both the effects of the tumor itself, and radiation therapy.