| Abstract: | The minimum angular size of a color stimulus required for its discrimination has been ascertained to be a quantitative criterion for evaluating the form and degree of congenital chromatic visual diseases. Unlike individuals with normal color perception who distinguish all basic and intermediate colors despite their saturation, anomalous trichromats discriminate more saturated colors with larger angular sizes of stimuli than those with normal color perception. Mild and moderate anomalous trichromats do not discriminate lowly saturated colors or for this they require the angular sizes tens of times greater those for normal trichromats. Persons with severe chromatic visual diseases (Type A) do not distinguish moderately saturated colors either. On recognizing the color of test objects, anomalous trichomats make the most mistakes in perceiving the green and yellow colors, the fewest mistakes in perceiving the red color. The minimum angular sizes required to distinguish colors, the percent of errors in their discrimination, and the range of vision of safety signs depend on the form and degree of congenital chromatic diseases. This makes it necessary to apply a differential approach to providing jobs that require rapid and accurate color discrimination in persons with the protanomalous forms of chromatic pathology. |
