The Mind's Eye by Oliver Sacks

The amazing Dr. Oliver Sacks wrote much of this book in 2005, when he was seventy-three and had just been treated for a melanoma at the back of his retina. This delicate procedure threatened the sight in his dominant eye, and he ably describes some moments of terror the cancer evoked.

Though Dr. Sacks eventually lost sight in the affected eye, he survived for ten years and published this and four more books, including the astonishing Musicophilia: Tales of Music and the Brain, which came out in 2010. Sacks's final book came out in 2017, two years after his death.

Like his other works, this volume is full of amazing patient stories, but this time, the storyteller -- as a neurologist, a patient and a man -- is more visible in the narrative.

He shares his passion for swimming and stereoscopy, and reveals his own neurological oddities: "I have had difficulty recognizing faces for as long as I can remember." Place recognition can also pose problems, making it necessary to avoid deviating from a particular route unless he is with a friend. "At the age of seventy-six, despite a lifetime of trying to compensate, I have no less trouble with faces and places. I am thrown particularly when I see people out of context, even if I have been with them five minutes before."

As always, the patients he describes suffer from odd brain-related symptoms, and he explains with affection and sympathy how different individuals cope with their losses. Jane Goodall, like Sacks himself, suffers from prosopagnosia, or face blindness, but as this is moderate, both "can, after repeated exposure, learn to identify those we love best."

Following a stroke, detective novelist Howard Engel found that he could still write, but was no longer able to read. It happened that his publisher, Scribner, also suffered from alexia. Both men not only found new ways of coping with their disabilities, they used "a handicap to hone a skill."

Capgras syndrome is a problem that causes patients to lose their sense of emotional connection to the faces of people they know and love. Lacking that "special warm feeling of familiarity, the Capgras patient will argue" that their loved ones "must be clever impostors, counterfeits."

In prelingually deaf people, the auditory parts of the brain remain active and functional, but they are reallocated to other functions. In a similar way, "the visual cortex, deprived of visual input, is still good neural real estate, available and clamouring for a new function."

Blindness can cause "a heightening of other senses," including "the ability to use sound or tactile clues to sense the size or shape of a space and the people and objects within it." The blind physician Dennis Shulman feels that he is "far more sensitive to others' emotional states since losing his sight." Indeed, he can recognize many patients by smell, and "pick up states of tension or anxiety they might not even be aware of."

The reader also learns interesting things about animals. Siamese cats are often born cross-eyed, and the ability to see in stereo is biologically crucial to many creatures. "Predators, in general, have forward-facing eyes, with much overlap of the two visual fields; prey animals, by contrast, tend to have eyes at the sides of their heads, which gives them panoramic vision, helping them spot danger even if it comes from behind."

Once again, a truly fascinating work by the great neurologist who wrote Hallucinations and The Man that Mistook his Wife for a Hat. The closing passage of the book refers to a "delicious" paradox, and reveals this remarkable doctor's zest for knowledge, and for life.