Unilateral Color Deficiency, Congenital and Acquired

The literature on unilateral color vision defects is reviewed, with particular reference to a unilateral deuteranope recently described by Graham and his associates and by Walls. A similar atypical unilateral deuteranomalous subject is described where the color vision defect has been acquired due to the disease retrobulbar neuritis. The hue discrimination and luminosity curves for this patient are compared with those found by Graham, and the possibility that retrobulbar neuritis could be responsible for a unilateral deutan defect with good visual acuity is discussed.