Wald, George, 1906–97, American biochemist, b. New York City, Ph.D. Columbia, 1932. He spent most of his career on the faculty at Harvard. In 1967 Wald, Haldan K. Hartline, and Ragnar Granit received the Nobel Prize in physiology or medicine with for their discoveries concerning the primary physiological and chemical visual processes in the eye. Wald was the first scientist to detect vitamin A in the retina, and he went on to identify three different types of retinal cone cells, each of which has unique protein pigments and enables the eye to react to a specific portion of the color spectrum.