A born and bred New Yorker, George Wald graduated from New York University in 1927 and received his Ph.D. five years later from Columbia University. For the next two years, Wald studied in Europe, working with two of the continent's most eminent chemists, Berlin's Otto Warburg and, in Zurich, Switzerland, Paul Karrer (1889-1971), a pioneer in vitamin A research. He then returned to the United States and, in 1934, joined the faculty of Harvard University, where he remained for the rest of his career.

From the start, Wald was primarily interested in the photochemistry of vision. In 1933, he had already discovered that vitamin A was a vital ingredient in the eye's retina, specifically in the pigments contained in the retina's rods and cones. The rods--the tiny rod-shaped cells that allow the eye to see in dim light--contained a pigment called rhodopsin. What exactly was the relationship between rhodopsin and...