pros·o·pag·no·si·a 
(prŏs′ə-păg-nōzē-ə, -zhə, prō′-)
(prŏs′ə-păg-nōzē-ə, -zhə, prō′-)n.
A disorder characterized by the inability to recognize people by their faces. In some cases it is present at birth, and in others it is the result of a brain injury. Also called face blindness.
[Greek prosōpon, face, character; see PROSOPOPEIA + agnōsiā, agnosia; see AGNOSIA.]
pro′so·pag·nosi·ac′ (-zē-ăk′), pro′so·pag·nosic(>-zĭk) adj. & n.