The quality of vision in patients with a diffractive multifocal intraocular lens was tested and compared to monofocal IOLs and to eyes with a beginning cataract. An automatic computer-assisted visual acuity and contrast-sensitivity test was used. Diffractive IOLs showed reduced contrast sensitivity in both dark contrast testing and bright contrast testing. The differences from monofocal IOLs were not statistically significant. Glare sensitivity was of the same degree in both IOL groups. In additional, visual acuity under reduced contrast conditions was measured at the Ocutrast with and without glare. There was no significant difference between IOL groups. The results obtained showed that contrast sensitivity with diffractive IOLs is not as good as with monofocal IOLs. In this study no significant differences were found.