Selig Hecht, recipient of the 1941 Frederick Ives Medal, was known for his substantial contributions to the study of photoreception and vision. One of his most famous findings was his determination that a minimum of 5-14 photons are required to produce a visual response in the human eye.
AIP Emilio Segrè Visual Archives, Physics Today Collection
Selig Hecht (1892-1947) was born in the village of Glogow, Austria (now Poland) and came to America as a young boy. He attended public schools in New York City’s lower east side neighborhood and was known as a hard-working and bright student. He spent his last summer vacation before college at the Bureau of Fisheries in Beaufort, N.C. In 1913, he earned a degree in biology at the City College of New York.
Hecht’s first job was as a chemist at an industrial fermentation research laboratory. He was tasked with studying the effect of light on beer—this was his first experience with photochemistry. After identifying and presenting his results, Hecht was promptly laid off. He was unhappy with his treatment in the lab and renounced industrial work in favor of graduate study. In order to save funds for school, Hecht worked as a chemist in the Department of Agriculture in Washington, D.C. Within a year he had saved enough to enter Harvard University’s graduate program in zoology.
Hecht’s summers were spent studying the physiology of marine filter-feeding organisms called tunicates (the subject of his doctoral dissertation) at the Bermuda Biological Station. He received his Ph.D. in June 1917. Hecht had entered a portion of his doctoral thesis for the Bowdoin Prize “for essays of high literary merit,” and was awarded two hundred dollars and a medal.
Hecht married the day after receiving his dissertation. He and his wife left shortly after the award for a honeymoon at the Oceanographic Institute at La Jolla, Calif., where Hecht would also complete a fellowship at the Oceanic Institute to conduct experiments on fish and clam light sensitivity. His experiments launched a lifetime of work on photoreception and vision. His research was published in the first issue of the Journal of General Physiology. From this point forward, nearly all of Hecht’s findings were published in the pages of that journal.
In the fall of 1917, Hecht took an assistant professor of biochemistry position at Creighton University, Neb. Hecht preferred urban environments and looked upon these four years as a period of exile. It was made more onerous by a lack of time and resources for his research. He escaped each summer to the marine biological laboratory in Woods Hole Oceanographic Institute, Mass. There, he eagerly compensated for the year’s frustrations and completed some of his most significant work.
Hecht eventually refocused his attention to the analysis of human visual function, specifically how the eye adapts to darkness. His research began with bleaching rhodopsin in solution to collect data on the initial effects of light on the eye.
Hecht was awarded one of Canada’s National Research Council fellowships in biology to further his study of human vision. He waited almost a decade after completing his formal training before he was offered an academic appointment. During this time, Hecht extended his view of the photoreceptor process to a theoretical analysis of brightness discrimination that combined human and clam data into one quantitative treatment. He proved that data on human light intensity discrimination consist of a low-intensity segment (dependent on the rods) and a high-intensity segment (governed by the cones). He also determined that at least 5-14 photons were needed to produce a visual response.
In 1926, Hecht was offered a post at Columbia University, N.Y., as a professor of biophysics. He held this post for the rest of his life. Hecht and his laboratory assistant Simon Shlaer built a succession of precise instruments for visual measurement, among them an adaptometer and an anomaloscope that have since gone into general use. While at Columbia, Hecht investigated dark adaptation, brightness discrimination, visual acuity, visual response to flickered light, the mechanism of the visual threshold and normal and anomalous color vision in humans. His lab also made important contributions to the biochemistry of visual pigments, the relationship between night blindness and vitamin A deficiency in humans, the spectral sensitivities of humans and other animals and plant reactions to light.
In 1941, Hecht was given OSA’s highest award, the Frederick Ives Medal for overall distinction in optics. He was elected to the National Academy of Sciences in 1944.
Later in his career, Hecht greatly enjoyed teaching adults at New York’s New School, where he gave courses in sensory physiology, physics and atomic energy. His lectures on atomic energy for lay audiences grew into the book, Explaining the Atom. A 1947 New York Times editorial called the book “by far the best so far written for the multitude.” After the end of World War II, Hecht became an honorary vice-president of the Emergency Committee of Atomic Scientists, a group striving to prevent military control of the U.S. atomic energy program. He was the only member of that small group who was not a nuclear physicist.
In July 1947, Hecht flew to England to meet up with old friends at the Oxford University physiological congress. Later, he attended a color vision conference in Cambridge and spent an absorbing week there in discussion and argument with most of Europe and America’s experts in vision. He reviewed the status of his own work during this time, making plans for the years ahead, before returning to the United States for his daughter’s wedding. Two weeks later he died suddenly, without long illness or apparent suffering. He was only 55.
Note: Portions of this column were drawn from the National Research Council’s “Biographical Memoirs,” published by the National Academies Press in 1991. Chapter six is dedicated to Hecht’s contributions to the field.
John N. Howard is the founding editor of Applied Optics and retired chief scientist of the Air Force Geophysics Laboratory.