Sacks wrote about face-reognition disorders in the title piece of his 1985 collection, "The Man Who Mistook His Wife for a Hat."

I’ve mentioned before that I have a neurological glitch, called prosopagnosia or face-blindness, which causes me problems with face recognition. I can see faces just fine, but I have trouble identifying them out of context. I’m usually okay with people I see on a regular basis, less so with those I run into infrequently or haven’t seen in a long time. It causes countless misunderstandings.

Thankfully, I don’t have  a very severe level of face-blindness, but Oliver Sacks does. It’s so bad for the doctor that he actually can’t recognize himself in a mirror. The neurologist writes about dealing with the disorder in his latest excellent collection of case studies, The Mind’s Eye. An excerpt from his essay, “Face-Blindness”:

“I just assumed that I was very bad at recognizing faces as my friend Jonathan was very good–that this was just within the limits of normal variation, and that he and I just stood on 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 thirty-five 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 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.

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.”