Prosopagnosia : from the Greek 'prosopon', face, and 'agnosia', not knowing. Sometimes called 'face-blindness'. Its related disorder, prosopamnesia, the inability to remember faces. The disorder is not common, and scientists are only beginning to study it deeply. There is no cure, and the adjustments required are personal and involve common-sense strategies, so there is nothing there to interest a pharmaceutical company. You may know someone who has it, and not be aware of it – though you may think he is unfriendly or 'stuck-up'. You may have it, and not know it, or be aware of it, but not know what it is called.

The inability to recognise or remember faces can leave you lost when you and your partner become separated in a crowd. Prosopagnosia can make parties a trial as you attempt to recognise people divorced from their native habitats. The condition will certainly render you useless as an eyewitness. 'Do you see the assailant in this courtroom?' 'Er, no. It might be the judge, as far as I can tell.'

The following is a personal account of living with the condition of prosopagnosia. The impetus to tell this story came from watching the film Faces