Photo from the Nobel Foundation archive.
The Nobel Prize in Physiology or Medicine 1967
Born: 30 October 1900, Helsinki, Russian Empire (now Finland)
Died: 12 March 1991, Stockholm, Sweden
Affiliation at the time of the award: Karolinska Institutet, Stockholm, Sweden
Prize motivation: "for their discoveries concerning the primary physiological and chemical visual processes in the eye."
Prize share: 1/3
Our vision works by the light around us being captured by a large number of light-sensitive cells located in the retinas at the back of our eyes. After a series of nerve switches and conversions of chemical and electrical signals, this results in visual impressions. Using very sophisticated electrodes, Ragnar Granit was able to study the electrical impulses from the retina's cells. In studies conducted from the 1930s to the 1950s, he demonstrated that there are different types of cones (the cells that enable color vision) and that these are sensitive to light of three different wavelengths.