He demonstrated the reaction to light of the substance retinal in the retinal rods, thus helping to explain the changes that take place in the eye during light and darkness.  
Born in New York City and educated at NYU and Columbia, in 1934 he joined the faculty at Harvard, becoming a full professor of biology in 1948.  He demonstrated the reaction to light of the substance retinal in the retinal rods, thus helping to explain the changes that take place in the eye during light and darkness.  He showed that the lack of retinal, which is formed from vitamin A, brings on night blindness in a person whose diet is deficient in that vitamin.  FTP, identify this American biochemist and Nobel laureate, who shared the 1967 Nobel Prize in physiology or medicine with the Swedish neurophysiologist Ragnar Granit and the American biophysicist Haldan Keffer Hartline.
Born in New York City and educated at NYU and Columbia, in 1934 he joined the faculty at Harvard, becoming a full professor of biology in 1948.  
George Wald