Abstract

Central dyschromatopsia is an acquired disorder of color vision caused by damage in the visual association cortex of the occipital lobe. Its existence, once questioned by Gordon Holmes, is no longer in doubt. Patients with the disorder may report that colors look "dirty," "dull," "faded," or "wrong" in the affected visual fields. In the worst cases they may report a visual experience of the world in shades of gray, as if viewed on a black-and-white television set. The pattern of psychophysical defects associated with such descriptions may provide insights on how signals from the short, long, and middle wavelength sensitive cones are processed at cortical levels. The problem, however, is that central dyschromatopsia usually affects a quadrant or hemifield and spares fixation, the region where most standard color tests are presented. Consequently, its psychophysical underpinnings remain poorly defined.

© 1992 Optical Society of America