Purpose To investigate the effect of virtual reality proficiency-based training on actual cataract surgery performance. The secondary purpose of the study was to define which surgeons benefit from virtual reality training. Design Multicenter masked clinical trial. Participants Eighteen cataract surgeons with different levels of experience. Methods Cataract surgical training on a virtual reality simulator (EyeSi) until a proficiency-based test was passed. Main Outcome Measures Technical performance in the operating room (OR) assessed by 3 independent, masked raters using a previously validated task-specific assessment tool for cataract surgery (Objective Structured Assessment of Cataract Surgical Skill). Three surgeries before and 3 surgeries after the virtual reality training were video-recorded, anonymized, and presented to the raters in random order. Results Novices (non–independently operating surgeons) and surgeons having performed fewer than 75 independent cataract surgeries showed significant improvements in the OR—32% and 38%, respectively—after virtual reality training (P = 0.008 and P = 0.018). More experienced cataract surgeons did not benefit from simulator training. The reliability of the assessments was high with a generalizability coefficient of 0.92 and 0.86 before and after the virtual reality training, respectively. Conclusions Clinically relevant cataract surgical skills can be improved by proficiency-based training on a virtual reality simulator. Novices as well as surgeons with an intermediate level of experience showed improvement in OR performance score.