HAYS, ISAAC (1796–1879), U.S. physician. Hays, a descendant of Michael Hays' son Isaac (see *Hays family), was born in Philadelphia. He graduated from the University of Pennsylvania (1816) and received an M.D. there (1820). An oculist, he was one of the pioneers in the study of astigmatism and color blindness, and he invented a scalpel for use in cataract surgery. Hays's contribution extended beyond his specialty. He was the editor of several important journals, one of the founding members of the American Medical Association (1847), and wrote the code of medical ethics which has been adopted throughout the United States.
Rosenbloom, Biogr Dict, s.v.Hays, Isaac3.