Overview of Refractive Surgery -- American Family Physician

Optics, Refraction and Refractive Error Refraction is the bending of light rays as they pass from one transparent medium to another medium of a different density; it is measured in diopters. The refractive power of a lens is the reciprocal of its focal length measured in meters (e.g., a one-diopter lens has a focal point of 1 m; a two-diopter lens has a focal length of 0.5 m). The cornea and the crystalline lens refract light that enters the eye. The cornea is responsible for two thirds of the eye’s total focusing power, while the crystalline lens accounts for the remaining one third. The focusing power of the cornea is fixed, whereas the focusing power of the crystalline lens is not. Through a process called accomE xtensive television, radio and newspaper advertising have promoted laser vision correction, and the public has a variety of refractive procedures from which to choose. Because of this media attention, many patients will be asking their family physician about these procedures. Family physicians should be familiar with the indications and contraindications of the refractive procedures, as well as the results, follow-up courses and potential complications.