BACKGROUND: Cataract surgery is the most common incisional surgical procedure in ophthalmology and is important in ophthalmic graduate medical education. Although most ophthalmology training programs in the United States (US) include virtual reality (VR) training for cataract surgery, comprehensive reviews that detail the impact of VR training on ophthalmology trainee performance are lacking. OBJECTIVES: To assess the impact of VR training for cataract surgery on the operating performance of postgraduate ophthalmology trainees, measured by operating time, intraoperative complications, postoperative complications, supervising physician ratings, and VR simulator task ratings. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), Ovid MEDLINE, Embase.com, PubMed, LILACS, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 14 June 2021. SELECTION CRITERIA: We included randomized controlled trials (RCTs) comparing VR training to any other method of training, including non-VR simulation training (e.g., wet laboratory training), didactics training, or no supplementary training in postgraduate ophthalmology trainees. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology. Primary outcomes were operating times in the operating room and intraoperative complications. Secondary outcomes were operating times in simulated settings, simulator task ratings, and supervising physician ratings, either in the operating room or simulated settings. MAIN RESULTS: We included six RCTs with a total of 151 postgraduate ophthalmology trainees ranging from 12 to 60 participants in each study. The included studies varied widely in terms of geography: two in the US, and one study each in China, Germany, India, and Morocco. Three studies compared VR training for phacoemulsification cataract surgery on the Eyesi simulator (VRmagic, Mannheim, Germany) with wet laboratory training and two studies compared VR training with no supplementary training. One study compared trainees who received VR training with those who received conventional training for manual small incision cataract surgery on the HelpMeSee simulator (HelpMeSee, New York, NY). Industry financially supported two studies. All studies had at least three domains judged at high or unclear risks of bias. We did not conduct a meta-analysis due to insufficient data (i.e., lack of precision measurements, or studies reported only P values). All evidence was very low-certainty, meaning that any estimates were unreliable. The evidence for the benefits of VR training for trainees was very uncertain for primary outcomes. VR-trained trainees relative to those without supplementary training had shorter operating times (mean difference [MD] -17 minutes, 95% confidence interval [CI] -21.62 to -12.38; 1 study, n = 12; very low-certainty evidence). Results for operating time were inconsistent when comparing VR and wet laboratory training: one study found that VR relative to wet laboratory training was associated with longer operating times (P = 0.038); the other reported that two training groups had similar operating times (P = 0.14). One study reported that VR-trained trainees relative to those without supplementary training had fewer intraoperative complications (P < 0.001); in another study, VR and conventionally trained trainees had similar intraoperative complication rates (MD -8.31, 95% CI -22.78 to 6.16; 1 study, n = 19; very low-certainty evidence). For secondary outcomes, VR training may have similar impact on trainee performance compared to wet laboratory and greater impact compared to no supplementary training, but the evidence was very uncertain. One study reported VR-trained trainees relative to those without supplementary training had significantly reduced operating time in simulated settings (P = 0.0013). Another study reported that VR-trained relative to wet laboratory-trained trainees had shorter operating times in VR settings (MD -1.40 minutes, 95% CI -1.96 to -0.84; 1 study, n = 60) and similar times in wet laboratory settings (MD 0.16 minutes, 95% CI -0.50 to 0.82; 1 study, n = 60). This study also found the VR-trained trainees had higher VR simulator ratings (MD 5.17, 95% CI 0.61 to 9.73; 1 study, n = 60). Results for supervising physician ratings in the operating room were inconsistent: one study reported that VR- and wet laboratory-trained trainees received similar supervising physician ratings for cataract surgery (P = 0.608); another study reported that VR-trained trainees relative to those without supplementary training were less likely to receive poor ratings by supervising physicians for capsulorhexis construction (RR 0.29, 95% CI 0.15 to 0.57). In wet laboratory settings, VR-trained trainees received similar supervising physician ratings compared with wet laboratory-trained trainees (MD -1.50, 95% CI -6.77 to 3.77; n = 60) and higher supervising physician ratings compared with trainees without supplementary training (P < 0.0001). However, the results for all secondary outcomes should be interpreted with caution because of very low-certainty evidence.  AUTHORS' CONCLUSIONS: Current research suggests that VR training may be more effective than no supplementary training in improving trainee performance in the operating room and simulated settings for postgraduate ophthalmology trainees, but the evidence is uncertain. The evidence comparing VR with conventional or wet laboratory training was less consistent.