Lasers and optics have affected health care in a myriad of ways. This paper surveys their impact on three aspects of health care: (1) surgery and medicine, (2) biology, and (3) biotechnology. In surgery, fiber optics have enabled the development of endoscopes, which allow access to most sites within the body. Endoscopes have, in turn, led to the development of minimally invasive therapy, which is changing the practice of surgery. Optics contributes to biology via new techniques for visualization, measurement and analysis, and manipulation. In biotechnology, broadly defined as the measurement, manipulation, and manufacture of large biologically significant molecules such as proteins and DNA, optical methods have become important in genetic sequencing and pharmaceutical development.