Color vision test

Human color vision is based on the perception of the three primary colors—red, green, and blue—by photosensitive pigments in the cone cells of the retina. When the proportions of these three photosensitive pigments are normal, it is called trichromacy. If only two are normal, it is called dichromacy, and if only one is normal, it is called monochromacy. Color vision testing assesses whether a patient's color vision is normal, including psychophysical tests (subjective tests) and visual electrophysiological tests (objective tests). Subjective tests: These include pseudoisochromatic plates (Ishihara charts), hue arrangement tests, and anomaloscopes, which are commonly used clinical methods. Objective tests: These include electroretinography and color visual evoked potentials.