OBJECTIVE The presence of cellular deposits on the surface of intraocular lenses (IOLs) is a manifestation of: (1) the breakdown of the blood-aqueous barrier produced by surgery; and (2) foreign body reaction induced by lens implantation. The purpose of this study was to assess the presence of cellular deposits on the surfaces of various IOL materials. METHODS Fifty patients scheduled for cataract surgery were randomized into five groups of ten patients each and received IOLs of the following materials: conventional polymethylmethacrylate (PMMA), surface-passivated PMMA, heparin-surface modified PMMA, poly-hydroxyethylmethacrylate (HEMA) hydrogel and silicone. Patients were examined at 7 days, 30 days, 90 days, and 180 days after surgery. All eyes were observed first via slit-lamp and then using a contact specular microscope for photographic documentation. RESULTS Small, spindle-shaped cells were observed on all IOLs in the early postoperative period. Epithelioid cells appeared approximately 30 days after surgery on all PMMA IOLs, but most particularly on conventional PMMA IOLs. No cells were observed on poly-HEMA and silicone IOLs. CONCLUSIONS The decreased number of epithelioid cells discovered in the early postoperative period may indicate a reduction in the inflammatory process induced by surgery. The permanence of epithelioid cells on IOL surfaces may be a sign of foreign body reaction. The results of this study indicated that poly-HEMA and silicone IOLs showed fewer cellular deposits than PMMA IOLs, suggesting that they may be better tolerated than PMMA IOLs.