ABSTRACT.Purpose: To examine pre-and postoperative visual interference, subjective symptoms and visual acuity in patients undergoing epiretinal membrane (ERM) surgery. Methods: A retrospective observational case series comparing 239 eyes in 231 consecutive patients with idiopathic ERM in a selected catchment area from 2002 to 2009. Demography, visual acuity (VA), lens status and subjective symptoms were analysed before and after the operation. Patients, healthy enough to participate at least 2 years post surgery, answered a questionnaire about their subjective functional impairment before and after the ERM peeling. Visual disturbance was assessed on a visual analogue scale (VAS) ranging from 1 to 100 mm. Results: The preoperative VA for the eyes in the study was median 0.40 logMAR (logarithm of the minimum angle of resolution) (range À0.1 to 1.22) resulted in VA of 0.22 logMAR (range À0.1 to 1.1), which is a statistical significant difference (p À). Of 180 patients contacted, answers were received from 103 (57%). Subjective visual disturbance assessed on the VAS showed a median of 70 mm (range 0-100) before surgery compared to a subjective disturbance median 27 mm (range 0-98) postoperatively. The change preoperatively to postoperatively was mean À34 mm (SD 31), median À37 (range À96 to 37), p À. Patients with much disturbance at baseline measured by VAS experienced more subjective benefit of the operation measured by the distance between the mark on the VAS preoperatively and postoperatively, p À, Spearman correlation coefficient. Conclusion: Patients with considerable preoperative disturbance benefit more from an operation than those with less disturbance.