- A form of dichromatism characterized by absence of the red-sensitive pigment in cones, decreased luminosity for long wavelengths of light, and confusion in recognition of red and green. [G. protos, first, + a- priv. + ops (op-) eye]
* * *prot·an·opia .prōt-ə-'nō-pē-ə n a dichromatism in which the spectrum is seen in tones of yellow and blue with confusion of red and green and reduced sensitivity to monochromatic lights from the red end of the spectrum
* * *n.a defect in colour vision in which affected individuals are insensitive to red light and confuse reds, yellows, and greens. Compare deuteranopia, tritanopia.
* * *pro·ta·no·pia (pro″tə-noґpe-ə) [prot- + 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, with loss of luminance and shift of brightness and hue curves toward the short-wave end of the spectrum, as in twilight vision. protanopic adj
Medical dictionary. 2011.