Prosopagnosia (also known as 'face blindness') refers to a severe deficit in recognizing familiar people from their face. While some people report a very selective impairment that only influences the recognition of faces, others find the deficit extends to the recognition of other stimuli, such as objects, cars, or animals. Many people also report deficits in other aspects of face processing, such as judging age or gender, recognising certain emotional expressions, or following the direction of a person's eye gaze. Finally, a substantial proportion of prosopagnosics report navigational difficulties.