Vishniac studied at Shanyavsky University in Moscow from 1914 to 1920, earning a Doctorate in Zoology. In 1917 he enrolled in a three-year course in medicine, sponsored by the Russian government, and received a medical degree. He moved to Berlin in 1918, where he worked at odd jobs and studied Oriental art at the University of Berlin.
In 1920 he returned to Shanyavsky University, having been appointed assistant professor of biology. For four years, beginning in 1936, Dr. Vishniac traveled throughout eastern Europe photographing the Jewish people. He left for France just prior to World War II, and was interned there for three months in a Vichy concentration camp.
In 1940 Vishniac sailed for the United States. He took up freelance portrait photography, but gave that up in 1950 when an opportunity to pursue his interests in photomicrography made it possible for him to freelance in that field. Then, in 1957, he was appointed research associate at the Albert Einstein College of Medicine in New York. In 1960 he was project director for the "Living Biology" film series, a project financed by a National Science Foundation grant, wherein a total of forty 16mm sound-color films for high school and college use would be produced. Vishniac was also involved in films of the series "The Vanished World of Central Europe Jewry." In 1961-62 he taught biology education at Yeshiva University in New York. He has been professor of creativity at Pratt Institute, New York University and Rhode Island School of Design. . In 1959 he was the subject of a film entitled The Worlds of Dr. Vishniac that covered his research into the physiology of protozoa, employing his own cinematographic techniques.
In 1915 Vishniac invented time-lapse cinematography, presenting in rapid review the sequential processes of growth or reproduction. He took the first photograph since 1885 of the world as seen through the eye of an insect - in this case a firefly.
He is one of the world's foremost photomicrographers, his chief subjects of interest being the physiology of abates, plasma circulation in unicellular plants and unsolved issues in microbiology. At the age of seven he fitted the lens of his camera over the eyepiece of a small microscope and took his first important picture, a photomicrograph of a cockroach's leg. The basic tech¬nique he has developed essentially involves the use of polarized light - ordinary light that has been passed through a calcite prism to make it vibrate in one plane (i.e., one color) only. Calling the technique "colorization," he passes the colors through devices that speed up some wave lengths and slow down others. The result is that the detail and the color of the image that reach the eye are greatly intensified. In his work Vish¬niac is adamant about preserving the natural col¬ors of microscopic organisms, emphasizing the third dimension, and, unlike many of his colleagues, will photograph microscopic animals only alive and in their free-swimming state. It takes extraordinary patience and time to accomplish these goals, but Vishniac's determination is apparent in his words: "Everything made by human hands looks terrible under magnification - crude, rough, and unsymmetrical. But in nature every bit of life is lovely. The more magnification that we use, the more details are brought out, perfectly formed."
Vishniac was former president of the New York Entomological Society and a Fellow of the New York Academy of Sciences, the Royal Microscopical Society (British) and the Biological Photographic Association. He was a member of the American Society of Limnology and Oceanography, the American Society of Protozoologists and the National Association of Biology Teachers.