There are actually three short books in one volume here. The Island of the Colour Blind focuses on the tiny Pacific atoll of Pingelap, where a very high number of the residents are totally colour blind. Sacks is a neurologist and visits the atoll to investigate the condition, try to work out what is causing it and helping people to overcome the worst effects of the condition. The worst effect for most people is not the lack of colour vision (there are wonderful descriptions here of how people with the condition have a much better visual sense of texture and movement than most people with full colour vision), Much worse is the extreme sensitivity to light and the lack of detailed vision in daylight. While sharing his findings about the condition, Sacks gives us an intimate portrayal of life on the atoll and the sealife surrounding it. It's an incredibly fascinating account.
The middle part of the book is set in Guam, where Sacks looks at the lytico-bodig neurological condition that affects a lot of people on that island. This account is also fascinating, but I sometimes found there was too much medical information for me!
The last part of the book Cycad Island takes us to Rota, an island where Sacks is particularly interested in the cycad trees. He's interested in them for two main reasons, firstly because they are an ancient and long lived type of tree (that Sacks himself grows in his greenhouse at home) and also because there seems to be a connection between the cycad trees and the colour blindness of the people on Pingelap. Cycads are known to be poisonous, yet their seeds are used in food throughout the areas where they grow. The cook has to follow very precise instructions for detoxifying the seeds before they are ready to eat but it seems likely that not all seeds are always fully detoxified. This part of the book is particularly fascinating with a wealth of information about cycads and an interesting exploration of their toxicity.
Overall, this is a compelling read for anyone interested in our relationship with the natural world.
The Island of the Colour Blind and Cycad Island by Oliver Sacks, published by Picador.
I reviewed this book for Brighton Blogger's 2012 Reading Challenge. I also recently reviewed Le Ton Beau de Marot by Douglas Hofstadter.