The optical resolution and contrast of 18 silicone and 18 polymethylmethacrylate (PMMA) intraocular lenses were determined before implantation in and after removal from rabbit eyes. A specially designed microphotographic system that allows documentation and comparison of the image quality of different lens types was used. Silicone intraocular lenses showed a mean axial resolution of 1.25, PMMA lenses showed 1.60, of an optotype analogous resolution target (1.0 = 20/20) at a 3 mm pupil opening preoperatively. At one to 16 weeks postoperatively, both types of IOLs demonstrated nearly unchanged resolution. Contrast, however, decreased to between 60% and 85% of the preoperative 100% standard. This decrease was due to precipitates deposited on the lens surface, to posterior capsule opacification, and to lens decentration.