- Colorblindness of the red-green type, also known as deuteranomaly or Daltonism. The term "Daltonism" is derived from the name of the chemist and physicist, John Dalton (1766-1844). Dalton was born in a village in Cumberland, England where his father, Joseph, was a weaver in poor circumstances. He was educated by his father and John Fletcher, teacher in a Quaker school. When Fletcher retired in 1778, Dalton took his place. In 1793 he was appointed teacher of mathematics and natural philosophy at New College in Manchester. In 1803 he put forth the facts embodied in his law of partial pressures: the pressure of a mixture of gases is the sum of the pressures which would be exerted separately by the several constituents if each alone were present. Dalton's reputation largely rests upon his great Atomic Theory. It was said of Dalton that "into society he rarely went, and his only amusement was a game of bowls on Thursday afternoons." Dalton described his and his brother's affliction of colorblindness with defective perception of red and green in the first scientific paper he published. It was entitled "Extraordinary facts relating to the vision of colours, with observation" (Mem Literary Philos Soc Manchester 5: 28-45, 1798). It is the first recognized account of red-green colorblindness.
* * *A congenital abnormality of the retina in which there are two rather than three retinal cone pigments (dichromatism) and complete insensitivity to middle wavelengths (green). [G. deuteros, second, + anopia]
* * *deu·ter·an·opia .d(y)üt-ə-rə-'nō-pē-ə n color blindness marked by usu. complete loss of ability to distinguish colorsdeu·ter·an·opic -'nō-pik, -'näp-ik adj
* * *n.a defect in colour vision in which reds, yellows, and greens are confused. It is thought that the mechanisms for perceiving red light and green light are in some way combined in people with this defect. Compare protanopia, tritanopia. See also colour blindness.
* * *deu·ter·an·o·pia (doo″tər-ə-noґpe-ə) [deuter- + an-1 + -opia] a dichromasy characterized by retention of the sensory mechanism for two hues only (blue and yellow) of the normal 4-primary quota, and lacking that for red and green and their derivatives, without loss of luminance or shift or shortening of the spectrum. It is an X-linked trait occurring in about 1 per cent of males, but only rarely in females. deuteranopic adj
Medical dictionary. 2011.