- inability to distinguish one or several chromatic colors, independent of the capacity for distinguishing light and shade.
- complete inability to distinguish colors of the spectrum, with all objects appearing as shades of gray, black, and white, varying only as to lightness and darkness; achromatopsia.
Origin of color blindness
1844, replacing Daltonism (after English chemist John Dalton, 1766-1844, who published a description of it in 1794); in figurative use, with reference to race or ethnicity, attested from 1866, American English. Related: color blind (adj.).
- Deficiency of color perception, whether hereditary or acquired, partial or complete.
A defect in perception of colors, caused by a deficiency of certain specialized cells in the retina that are sensitive to different colors. The condition may be partial (as in “red-green colorblindness,” in which a person cannot distinguish red from green), or complete (in which the person sees all colors as gray).