Prosopagnosia (syn. face blindness) describes an inborn or acquired deficiency of face perception. In probands with this anomaly the ability to recognize even familiar faces is impaired, whereas faces expressing emotions, attractiveness and gender are clearly seen. In contrast to the acquired form, which is easily diagnosed by the sudden loss of a skill, the congenital form is mostly overlooked. Nevertheless, prosopagnosia is very common and almost always hereditary. Once alerted to this phenomenon it is found by chance – sometimes hidden - in a variety of sources as in autobiographies, poems, celebrities in live radio/TV programmes, and even one’s own close friends. Almost all of the subjects think their problem is unique, and in cases with the very frequent hereditary form, nearly all of the affected individuals were not aware of other impaired first-degree relatives.