1) Tetartanopia 
(tet″әr-tә-nop´se-ә) tetartanopia.
tetartanopia, tetartanopsia 1. Defective vision or blindness in one fourth of the visual field. 2. A rare type of dichromatic vision (defective color vision in which one of the three cone pigments is missing) of doubtful existence, characterized by perception of red and green only, with blue and yellow perceived as an achromatic (gray) band.