As the post-keratorefractive surgery patient population ages, visually significant cataracts will develop. As surgeons gain experience with cataract extraction in post-refractive surgery patients, they are finding that standard and routine IOL formulas and keratometry can lead to "refractive surprises", which may require subsequent surgical correction. Common results are underestimation of IOL power and unexpected hyperopia in patients who have undergone corneal refractive surgery to correct myopia. This paper reviews the current clinical experience with intraocular lens power determination after cataract surgery in post-keratorefractive patients, provides an overview of possible sources of error in intraocular lens power calculation in these patients, and analyzes methods to minimize intraocular lens power errors and improve accuracy.