I assumed that I was just very bad at recognizing faces, as my friend Jonathan was very good — that this was within the limits of normal variation, and that he and I just stood at opposite ends of a spectrum. It was only when I went to Australia to visit my older brother Marcus, whom I had scarcely seen in 35 years, and discovered that he, too, had exactly the same difficulties recognizing faces and places that it dawned on me that this was something beyond normal variation, that we both had a specific trait, a so-called prosopagnosia, probably with a distinctive genetic basis.
That there were others like me was brought home in various ways. The meeting of two people with prosopagnosia, in particular, can be very challenging. A few years ago, I wrote to one of my colleagues to tell him that I admired his new book. His assistant then phoned Kate [my assistant] to arrange a meeting, and they settled on a weekend dinner at a restaurant in my neighborhood.
"There may be a problem," Kate said. "Dr. Sacks cannot recognize anyone."
"It's the same with Dr. W.," his assistant replied.
"And another thing," Kate added. "Dr. Sacks cannot find restaurants or other places; he gets lost very easily — he can't even recognize his own building sometimes."
"Yes, it's the same with Dr. W.," his assistant said.
Somehow, we did manage to meet and enjoyed dinner together. But I still have no idea what Dr. W. looks like, and he probably would not recognize me, either. Although such examples may seem comical, they are sometimes quite devastating. People with very severe prosopagnosia may be unable to recognize their spouse, or to pick out their own child in a group of others.
Jane Goodall also has a certain degree of prosopagnosia. Her problems extend to recognizing chimpanzees as well as people — thus, she says, she is often unable to distinguish individual chimps by their faces. Once she knows a particular chimp well, she ceases to have difficulties; similarly, she has no problem with family and friends. But, she says, "I have huge problems with people with 'average' faces.… I have to search for a mole or something. I find it very embarrassing! I can be all day with someone and not know them the next day."
Excerpted from The Mind's Eye by Oliver Sacks Copyright © 2010 by Oliver Sacks. Excerpted by permission of Knopf, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher. Read an interview with Oliver Sacks.