Radial keratotomy surgery was begun in a private ophthalmologic practice in July 1980. A statistical analysis of the first 557 cases is presented. The mean postoperative refractive error was -4.00 diopters. One year after surgery, 95% of the patients with a preoperative refractive error of -3.00 diopters or less had a visual acuity of 20/40 or better, and 79% of those with a refractive error of -3.25 to -6.00 diopters had a visual acuity of 20/40 or better. The mean decrease in keratotomy readings at six months postoperatively was 2.95 diopters. Of the patients with a preoperative refractive error of less than 6 diopters, 85% wore glasses rarely or not at all, whereas 15% wore a refractive correction full time.