color blindness

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Related to Protanope: deuteranope, 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 ?
R] values similar to those provided by real protanopes but not by real deuteranopes.
Group I: (Out of 85 subjects) Red-green deficiency: 16 (8 protanopes, 8 deuteranopes).
Experiment 4 was designed to be performed by protanopes, an observer type with a pattern of spectral sensitivities that is the opposite of that of the tritanomalous: higher sensitivity to the left portion of the spectrum but lower sensitivity to the right portion.
Because of their genetic origin (Birch, 1993), protanopes offer two important advantages for research.
The protan group was made up of two protanopes (men, 28 and 34 years).
However, protanopes showed increases in response times of 35% for R and 53% for Y.
For example, our deuteranopes showed the greatest increases in response time--53% for R signals and 85% for Y signals, relative to those of normals--whereas protanopes showed increases in response times of 35% for R signals and 53% for Y signals.
1) Mean position of the center cap Range Protanopes 17 15-26 64 58-68 Deuteranopes 15 12-17 58 53-60 Tritanopes 5 4-6 45.