Purpose; To compare ocular performance and quality of vision in pseudophakic eyes with an aspherical intraocular lens (IOL) or a conventional spherical IOL. MthQ4s: 10 patients who had unilaterally implantation of the Tecnis Z9000 IOL and 10 patients who had unilaterally implantation of the Acrysof SN6OWF IOL were included in the trial. Eight weeks afler surgery, the following parameters were assessed: uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), visual evoked potential (VEP), microperimetry, contrast sensitivity and aberrometry. Patients with IOL selections (using SRK!T- axial length> 22.0 mm) outside the range of +10.0 to +30.0 diopters (D) were excluded affer biometry using the lOLMaster (Zeiss). i{es!11frs: The mean best visual acuity (1ogMAR) was 0.04±0.07 in the Tecnis group and 0.02±0.07 in the Acrysof group (p=O,52). VEP in all spatial frequencies examined were not different between the 2 groups cosi come data obtained by microperimetry. Mesopic contrast sensitivity at high, intermediate and low spatial frequencies were not statistically different between groups. Spherical aberration (Tecnis 0,00 jim ± 0,05; Acrysof +0,15±0,07 tm) were significantly lower in patients with the TecnislOL than patients with acrysoflOL (p< 0,001 andpo,006). Conduskns Results show the Tecnis Z9000 IOL with a modified anterior aspheric surface induced significantly less higher-order aberration and spherical aberration compared with the Acrysof SN6OWF IOL.