Also known as dichromatopsia, dyschromatopsia, and parachromatopsia. The term dichroma-tism comes from the Greek words dis (twice) and chroma (colour). It refers to a type of *colour vision deficiency in which one of the three colour receptor mechanisms is missing. Dichromatism is absolute, due to the absence of one type of retinal cone pigment. In trichromatic species such as humans there are three types of dichro-matism, called *protanopia, *deuteranopia, and *tritanopia. The term dichromatism is used in opposition to the terms *monochromatism and *anomalous trichromatism.
References
Hsia, Y., Graham, C.H. (1965). Color blindness. In: Vision and visual perception.Editedby Graham, C.H. New York, NY: John Wiley & Sons.
McIntyre, D. (2002). Colour blindness. Causesand effects. Chester: Dalton Publishing.
Dictionary of Hallucinations. J.D. Blom. 2010.