ABSTRACT
Corneal refractive surgery corrects refractive errors by modifying the anterior surface of the cornea. The problem appears years later when, as a result of the normal aging process, these patients develop cataracts and require lens extraction surgery and intraocular lens (IOL) implantation. Figure 5.1 shows one eye with cataract surgery after corneal refractive surgery. The question arises about which should be the basis for calculating this lens implant. Being able to determine the accurate power of the IOL to be implanted in a patient undergoing cataract surgery is a big challenge, even more so when the patient has had prior refractive surgery. A patient with prior refractive surgery is very special both medically and psychologically because he or she will not want to use glasses permanently after having spent time without them.
