Refractive aspects of cataract surgery.

Cataract surgery has progressed to the point where it can now be performed so as to leave most patients emmetropic or with a predetermined amount of ametropia. The two major factors responsible for this prediction accuracy are intraocular lens power calculation and the control of surgically induced astigmatism. Recent theoretical intraocular lens power formulas are more accurate owing to their improved methods for predicting the postoperative anterior chamber depth. Additionally, there are more reliable methods for determining surgically induced astigmatism as well as methods for its control. Various combinations of wound architecture, wound closure, and astigmatic keratotomy and their effect on surgically induced astigmatism are reviewed.