color blindness

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Related to Colour-blindness: protanopia

color blindness,

visual defect resulting in the inability to distinguish colors. About 8% of men and 0.5% of women experience some difficulty in color perception. Color blindness is usually an inherited sex-linked characteristic, transmitted through, but recessive in, females. Acquired color blindness results from certain degenerative diseases of the eyes. Most of those with defective color vision are only partially color-blind to red and green, i.e., they have a limited ability to distinguish reddish and greenish shades. Those who are completely color-blind to red and green see both colors as a shade of yellow. Completely color-blind individuals can recognize only black, white, and shades of gray. Color blindness is usually not related to visual acuity; it is significant, therefore, only when persons who suffer from it seek employment in occupations where color recognition is important, such as airline pilots, railroad engineers, and others who must recognize red and green traffic signals. Tests for color blindness include identifying partially concealed figures or patterns from a mass of colored dots and matching skeins of wool or enameled chips of various colors.

Color Blindness


the inability to distinguish colors. Total color blindness (monochromatism), in which no color differences can be distinguished, is rare. (SeeDALTONISM for a discussion of partial color blindness.)

color blindness

[′kəl·ər ‚blīnd·nəs]
Inability to perceive one or more colors.
References in periodicals archive ?
In Pakistan and other Asian countries major cause of colour-blindness is inbreeding and consanguinity (cuisine marriages).
A person with red/green colour-blindness perceives different shades of red as dull and indistinct.
A Tory insider said Mr Hague suffered a "classic case" of colour-blindness, muddling up colours near to each other in the spectrum, such as blues, greens, browns and reds.
YOU wouldn't have thought snooker would be an ideal choice of sport for someone with a colour-blindness problem.