Through his research on xerophthalmia, karatomalacia and night blindness Wald revealed the critical function of vitamin A in normal vision and visual pathology.

(Thanks to Juan Weiss for this reference and their interpretation.)

In 1967 Wald shared the Nobel Prize in Physiology or Medicine with Ragnar Granit and Haldan Keffer Hartline "for their discoveries concerning the primary physiological and chemical visual processes in the eye."  See also Nos. 14276, 14277

In this paper Wald identified structures for all the visual pigments and their peak absorption wavelengths. He detailed the function of the rods and cones and broke down visual photonic perception at the molecular level, revealing the molecular basis of vision.

(Thanks to Juan Weiss for this reference and its interpretation.)

Continuing his research on retinal pigments structure and function with emphais on rhodopsin, Wald deciphered the interconversion of rhodopsin to retinene to Vitamin A.

(Thanks to Juan Weiss for this reference and its interpretation.)