A hereditary disorder of sight due to a lack of cone vision - that type of vision provided by the cone photoreceptors in the retina. In the normal eye, there are some 6 million cone photoreceptors; they are located largely in the center of the retina. Lacking cones, persons with achromatopsia have to rely on their rod photoreceptors. There are abou [..]

Severely deficient Color Perception, typically with monochromacy and reduced Visual Acuity. The atypical form can include normal Visual Acuity with pseudomonochromacy.

A severe congenital deficiency in colour perception, often associated with nystagmus and reduced visual acuity. Synonyms: achromatic vision, monochromasia, monochromasy, monochromatism. Origin: G. A-priv. + chroma, colour, + opsis, vision (05 Mar 2000)

A specific deficit in the perception of colors due to cortical lesions in the fusiform gyrus. Action Potential