As the eye surgeon adjusts the operating microscope, or aligns his laser beam, he should pause and reflect; his sophisticated specialty comes from a very humble beginning. In a medical dictionary written in 1795, G. Motherby simply divides eye disease into ophthalmia of an inflammatory nature, and an ophthalmia that included everything else. We are told that some of the major causes of ophthalmia are cold air, dust, and overexposure to vivid colors. Interestingly enough, at about the same time, Newton, Huygens, Descartes, and Kepler were formulating the laws of optics. The paths of science and medicine seemed worlds apart at that time. Who would be able to convince those medical men of yesterday that optics and mathematics could help the red, tearing, dim-sighted eyes of their patients? Indeed, mental giants were needed. Fortunately, there were such giants walking the stage of European science in the mid 19th century. Helmholtz invented the ophthalmoscope, and all at once the fundus could be seen, and many mysterious cases of blindness were understood on a rational basis. Donders taught refraction, and sud¬ denly a branch of medicine was closely intertwined with mathematics. Oth¬ ers, like Javal, Muller, and Purkinje, continued to add modern instrumen¬ tation and quantitative analysis to the specialty. There is no doubt that our present high level of development has its roots in physiological optics, its instru¬ ments, its theories, and, most impor¬ tant, its scientific method, which can be used to attack any problem in the medical field. Drs. Campbell, Koester, Tittler, and Tuckaberry have produced a volume that surveys physiological optics in its current state. The task must have been difficult, for the information accumulated on the subject in the last 125 years is enormous. The authors have successfully compressed the na¬ ture of light, geometric optics, and spectacle optics into readable, wellillustrated chapters. Sections on the principles of various pieces of opthalmic equipment are also clearly written and well illustrated. Finally, there are compact, but lucid, sections on visual perception and color. Are there any mistakes in the book, or did it leave out anything impor¬ tant? Very little, although the authors might have included sections on laser coagulation, light scattering, and the objective refractometer. Personally, I would have appreciated a greater sense of history permeating the mat¬ ter-of-fact chapters. The book is useful for anyone preparing for a board examination or for someone simply interested in learning the basic principles behind the many clinical examinations we perform. David Miller, MD Boston