The main advantage of phacoemulsification is lost when the 3 mm incision has to be enlarged to at least 6 or 7 mm to permit the insertion of a PMMA lens. The major reason for the development of soft IOL is their flexibility which allows them to be folded and introduced through a small incision. We began a clinical study to determine the safety and efficacy of a new silicone lens, which is a single piece, injection molded, flexible implant. 25 patients undergoing extracapsular cataract extraction were included in this study. The silicone lens was inserted flat through the wound and the desired position was sulcus fixation. After a one year follow up period, the results were compared with those of 207 patients implanted with PMMA lenses. The visual results and the mean endothelial cell loss were similar in both groups. Iris capture was seen in 4 cases of soft lenses, probably due to the minimal haptic rigidity. Long term in vivo studies in the unique environment of the eye will be necessary to establish the biocompatibility of new soft intraocular lenses.