BACKGROUND: At present, preoperative estimation of the influence of intra-ocular lenses (IOL) on visual performance, that is not only based on visual acuity but on the whole contrast sensitivity function (CSF), is only possible with high efforts. METHODS: We describe a method to evaluate the CSF of a patient after IOL implantation. The method is based on the knowledge of a normal subject's CSF, and the modulation transfer function of the IOL that can be measured or computed. RESULTS AND DISCUSSION: Comparison of computed and measured CSF with monofocal and multifocal IOL shows that the method allows prediction of visual performance after implantation of the IOL.
