Objective To investigate the value of hand-held retinal optometer and optical coherence tomography (OCT) in predicting postoperative visual acuity in patients with age-related cataract and idiopathic macular epiretinal membrane. Methods We retrospectively analyzed the data of patients undergoing phacoemulsification combined with intraocular lens implantation for age-related cataract in our hospital from January, 2019 to April, 2020. Preoperative examination detected idiopathic macular epiretinal membrane in 45 of the patients (52 eyes) with lens opacity grade C2N2P1 according to LOCSⅡ lens opacity classification criteria. Based on the thickness of the macular fovea, the eyes were divided into group A (9 eyes) with macular thickness <300 μm by OCT examination, group B (25 eyes) with macular thickness of 300 to 400 μm, and group C (18 eyes) with macular thickness >400 μm. The best corrected visual acuity and retinal visual acuity before operation and the best corrected visual acuity on the first day and at 3 months after the surgery were compared among the 3 groups. The consistency between the preoperative retinal vision and the best corrected vision at 3 months after the surgery was analyzed. Results The best corrected visual acuity at one day and 3 months after the surgery differed significantly from that before the surgery in all the 3 groups (P<0.05). The best corrected visual acuity recovered to 0.3-0.5 in most of the patients in the 3 groups. Thirty-one (91.18 %) of the patients with a macular thickness less than 400 μm had a visual acuity≥0.3 after cataract surgery, as compared with only 14 patients (77.78 % ) among those with a macular thickness >400 μm. There was a positive linear correlation between preoperative retinal visual acuity and best corrected visual acuity at 3 months after the surgery (r=0.830, P< 0.05). Conclusion For patients with cataract and idiopathic macular epiretinal membrane, phacoemulsification combined with intraocular lens implantation can improve postoperative vision. Hand-held retinal optometer can accurately assess postoperative vision in patients with stage C2N2P1 cataract. Patients with a macular thickness >400 μm caused by idiopathic macular epiretinal membrane are likely to have poor postoperative visual outcomes.