While refractive surgery such as radial keratotomy, epikeratophakia, and corneal relaxing incisions offer many potential benefits to patients, they can also generate optical problems such as overcorrection or undercorrection of the prior refractive error and variable vision. The authors offer suggestions for avoiding problems through proper patient selection; candid preoperative communication with the patient about possible difficulties and limitations; understanding of the physiological changes that may occur; and optical techniques for alleviating postoperative vision problems.