ABSTRACT: This study investigated postoperative changes in metamorphopsia and aniseikonia in eyes that underwent vitrectomy for epiretinal membrane (ERM), macular hole (MH), or rhegmatogenous retinal detachment (RRD). In total, 166 eyes were included from 166 patients with ERM, MH, or RRD who underwent primary vitrectomy. Metamorphopsia and aniseikonia were quantified by M-CHARTS and the New Aniseikonia Test (NAT). Best-corrected visual acuity (BCVA), M-CHARTS, NAT assessments, and OCT examination were performed at 1, 3, and 6 months postoperatively. Of the 166 eyes, 65 had ERM, 21 had MH, 42 had macula-off RRD, and 38 had macula-on RRD. BCVA improved significantly between 1 and 6 months postoperatively in eyes with ERM, MH, and macula-off RRD (P = 0.0057, P = 0.0065, and P = 0.0021, respectively). M-CHARTS scores at 1 month postoperatively significantly decreased in eyes with ERM (P = 0.0034) and tended to decrease in eyes with MH (P = 0.068). NAT scores did not change between baseline and 1 month postoperatively in eyes with ERM or MH. Between 1 and 6 months postoperatively, M-CHARTS and NAT scores significantly decreased in eyes with macula-off RRD (P = 0.0064 and P = 0.0009, respectively), but not in eyes with ERM, MH, or macula-on RRD. At 6 months postoperatively, significant metamorphopsia was evident in 33.3% of eyes with ERM, 29.2% of eyes with MH, and 35.7% of eyes with macula-off RRD; 61.5% of eyes with ERM showed macropsia and 52.3% of eyes with macula-off RRD showed micropsia. In eyes with ERM, more central retinal thickness (CRT) correlated with postoperative BCVA, and deep retinal folds on enface OCT image correlated with postoperative metamorphopsia. In eyes with macula-off RRD, less CRT correlated with postoperative BCVA, and tended to correlate with postoperative micropsia. Macular morphologies could contribute to differences in postoperative visual acuity, metamorphopsia, and aniseikonia.