Work

Our vision functions because light from the surrounding world is captured by many light-sensitive cells in the retina at the back of the eye. George Wald found that vitamin A is an important component in rhodopsin, a light-sensitive substance in the retina, and explained in a series of studies from the 1930s to the 1960s how light causes rhodopsin to change form and be converted. This conversion gives rise to signals in a complicated network of nerve cells by which a number of reconnections and transformations occur before the signals eventually are transformed into visual impressions in the brain.