Vision is an oft-unappreciated phenomenon, according to a noted biomedical engineer, who will present a talk on campus this week describing the intricacies of sight.

Biomedical engineer Jerome J. Lettvin of the Massachusetts Institute of Technology will visit the campus Wednesday and Thursday, Jan. 27 and 28, as a guest of the Tetelman Fellowship at Jonathan Edwards College. On Thursday at 5:15 p.m., the scientist will present a lecture titled "In a Frog's Eye: The Physiology of Vision" at the Yale University Art Gallery lecture hall, entrance on High Street. On Friday at 4 p.m., Lettvin will be the guest at a tea at Jonathan Edwards College master's house, 70 High St. Both events are free and open to the public.

"Seeing is so commonplace that we overlook its mystery," contends Lettvin. "Analyzing frog vision, for example, strains ordinary language because ideas which are familiar in practice are hard to word. Nevertheless, the concepts are easy to grasp ..." While the process of seeing begins with the sensing of the optical image by the cones and rods of the eye, it also requires that the brain process that information, explains the scientist. "It is a question of engineering rather than science ... knowing what the system does is a guide to how it works," he says.

Lettvin began his career as a neuropsychiatrist, having earned his medical degree at the University of Illinois College of Medicine. In 1948, he joined the staff of the Manteno State Hospital in Illinois as a psychiatrist. There, with the help of his colleagues (W. Pitts, W.S. McCulloch, P. Wall and P. Dell), Lettvin built his own physiology laboratory there, where the team studied the activity of mammalian spinal cords. In 1951, the group joined the Research Lab of Electronics at M.I.T., and Lettvin eventually became a professor in the departments of biology and of electrical engineering and computer science. After retiring in 1988, he joined the faculty of Rutgers University as the New Jersey Professor of Biomedical Engineering. For the past five years, as a member of the emeritus faculty at M.I.T., Lettvin has been doing research on the physiology of dyslexia with Gad Geiger.