Endothelial protection (measured by vital-dye staining and computerized planimetry) and viscoelastic retention during phacoemulsification with and without traumatic lens implantation were assessed in a rabbit model comparing four viscoelastics (Healon, Amvisc Plus, Occucoat, and Viscoat). No significant differences in cell damage were noted between unoperated on controls and groups that underwent atraumatic phacoemulsification with viscoelastic. Cell damage after traumatic lens insertion was reduced significantly by all four viscoelastics. Cell damage with and without traumatic lens implantation was significantly lower when viscoelastics were retained. Viscoat and Occucoat were significantly more likely to be retained than Healon.