I have a distinct memory of an article by Sacks that I read in the New Yorker a few years ago - one from his Musicophelia collection. I was impressed by the very lucid and yet evocative tone of his writing. My overwhelming impression, which is confirmed on reading The Mind's Eye, was that Sacks's main preoccupation was in trying to effectively communicate the experience of living in a world which is consistently mediated and distorted by a wayward mind. The science comes second; what is most interesting here is the attempt to hammer home the subjectivity of our everyday realities and the very frailness of our sensual understanding of the universe.
The Mind's Eye is best read as a series of discrete articles on a theme; anyone looking for a specific unifying arc for these case studies will be disappointed. Insights gained in one case rarely directly inform another, but on the other hand each story passed through here shows another way in which a life can be fundamentally altered by a chance impairment. Most curious for me is the musician who loses, first, her ability to sight read, and then gradually the capacity distinguish visually between concrete objects, to the extent that she can't tell a window from a wall - and beyond even that. She can distinguish between fruits by squeezing them, but when presented with them has no idea what she is looking at - even though her eyes themselves are functioning perfectly well. More and more is lost, more and more astonishingly.
The author's own experience with a retinal tumor stands out in a slightly different way, as his intimacy with the subject allows Sacks's tendencies towards the poetic to really flourish when he is describing, for example, peculiar feelings of half-blindness, of people's top halves being chopped off, and strange anomalies floating into his field of view, and of his brain working overtime to fill in the gaps. How might it feel stare at a point in the distance, a quarter of your view obscured by a tumour, and watch as the mind gradually fills the missing space with best-guess details? He does his best to explain, and often does a great job, although from time to time the descriptions become somewhat florid. Excerpts from his diaries at the time sometimes seem paranoiac and melodramatic; but I suppose they would!
On the whole this is a really interesting book. It perhaps lacks depth, but where it really excels is in its ability to push you towards understanding that what you see isn't always really what you get.