This randomized, single-masked, multicenter clinical trial, comprising 95 patients enrolled at five sites, evaluated the performance of AMO Vitrax and Healon viscoelastic materials during cataract surgery. Patients were examined preoperatively and at one day, four days, one month, and three months postoperatively. The following measurements were recorded and analyzed: percentage of endothelial cell loss from preoperative to three months postoperative; change in intraocular pressure (IOP) from preoperative to 24 hours postoperatively; postoperative corrected visual acuity; subjective assessment of ability of viscoelastic to create and maintain tissue space; intraocular transparency; ease of evacuation. Three months postoperatively, endothelial cell loss was 4.9% (+/- 8.3%) for the AMO Vitrax group and 6.3% (+/- 10.5%) for the Healon group. One day postoperatively, IOP decreased by 1.6 mm Hg and increased by +1.1 mm Hg, respectively. Postoperative visual acuities were similar between the two groups at three months. Subjective assessment of transparency was higher for Healon. Assessment of tissue space maintenance was similar between the two materials. Healon was rated as slightly easier to evacuate.