Why retire when you can make TV programmes on tropical islands of the Pacific? This book was written by Sacks in his early sixties and pursues his obsessions with neurology. Islands are strange places where populations of humans and animals are trapped - with potentially peculiar results that attract story-telling scientists like Sacks.
Here are populations of the genetically colour blind who cannot on these bright blue atolls stand bright light. Sacks takes along a Norwegian fellow scientist who also has congenital achromatopsia and together they set off with a film crew and a large stock of sunglasses. The story is saved from being simply a medical sight-seeing trip by virtue of Knut Nordby's presence as a fellow sufferer and his ability to share with the islanders of Pingelap the causes of the affliction, and reassure mothers that their children will not go blind - as well as the rather sensible offer of sunglasses.
There are some wonderful visual images in Sacks' writing - of the child that could not see before he was given his glasses `running down the hill, visored, like a young knight, shouting `I can see, I can see.' And there are sensible comments about how much this invisible problem is ignored in the face of other more pressing medical problems by the archipelago's few doctors. Nevertheless, the story reads rather like an exotic holiday trip with footnotes on ancient ruins and tales of the desecrations of colonial disease and environmental disaster that created such small populations that recessive genes took real hold. It builds on this impression by drawing on the accounts of early explorers and shipwrecked mariners - the kinds of tall tales that attracted a great readership in the nineteenth century.
Sacks self consciously models himself on a nineteenth century approach to narrative - whether it is erudite knowledge of obscure plant forms such as the cycads, or the case histories of incurable patients experiencing some huge unalterable challenge to their lives. He has a field day going round with a neurologist in Guam - no one has solved the puzzle of why pockets of the Guam population born before 1952 but not after are particularly susceptible to a mixed form of motor neurone disease and parkinsonism - lytico-bodig in the local language. His favourite theory is the cycads - he loves looking at these. I am sure the photos of flowers are up on his wall at home. They may have poisoned the population - they probably have not. But if not, what else happened? While he fails to find out, he explores a beautiful tropical island, and meets many families who look after their increasingly afflicted relatives very much as part of the community. Sometimes, you feel Sacks is looking at people in the same way that he does the cycads and the tropical fish - but his feelings of empathy and interest in people's lives also come across strongly - as does his commentary from long years of experience on the way these communities look after the disabled and the dying.