PURPOSE: To compare the incidence and intensity of posterior capsule opacification (PCO) and neodymium- yttrium-aluminum-garnet (Nd:YAG) capsulotomy rates between 2 similar open-loop single-piece hydrophobic acrylic intraocular lenses (IOLs) that differ in the proprietary material characteristics and design features, over a period of 3 years. DESIGN: Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison. METHODS: SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. PATIENT POPULATION: Eighty patients (160 eyes) had bilateral cataract surgery and received a Vivinex XY1 IOL in 1 eye and an AcrySof SN60WFIOL in the other eye. OBSERVATION PROCEDURES: Follow-up examinations were performed 3 years after surgery. Digital retroillumination images were taken of each eye. The amount of PCO (score: 0-10) was assessed subjectively at the slit lamp and objectively using automated image analysis software (AQUA). MAIN OUTCOME MEASURE: PCO score (scale, 0-10). RESULTS: The mean objective PCO score of the Vivinex XY1 IOLs was 0.9 +/- 0.8 compared to the PCO score of 1.4 +/- 1.1 for the AcrySof SN60WF IOLs (P < .001). Three years postoperatively, 11.4% of patients had an Nd:YAG capsulotomy in the Vivinex XY1 eye and 18.6% had a capsulotomy in the AcrySof SN60WF eye (P = .23). CONCLUSION: The new hydrophobic acrylic Vivinex XY1 IOL showed significantly lower PCO rates and lower YAG rates compared to the AcrySof SN60WF IOL. The interaction of various factors such as hydrophobic material, smooth optic surface, and sharp posterior optic edge plays a key role in PCO development. (C) 2020 The Authors. Published by Elsevier Inc.