Use of modified X-Chrom for relief of light dazzlement and color blindness of a rod monochromat.

A young female rod monochromat is treated optometrically with binocular contact lenses to relieve light dazzlement and a monocular lens to improve hue discrimination. A comparative study of various absorption contact lenses results in treatment of both problems with modified X-Chrom. A hypothesis is offered to explain the physiological aspects of relief. This paper also describes her visual experiences from an early age, her signs and symptoms of typical rod monochromacy and the methods of diagnosis. It is a brief historical account comprised of theories and references of contributors to scientific information.