Purpose: To elucidate the impact of mild PCO on the visual outcomes in patients with hydrophilic trifocal IOLs, and to identify objective indicators that can assist in determining the need for Nd:YAG laser capsulotomy. Methods: This is a prospective observational study. 189 patients implanted trifocal IOL who underwent Nd:YAG laser posterior capsulotomy were recruited. Patients were classified into four grades according to PCO morphology. The distance, intermediate, and near visual acuity (VA), dysfunction lens index (DLI), contrast sensitivity (CS) and visual function (VF-14) scores were measured before and 1 month after Nd:YAG laser capsulotomy. Results: Before Nd:YAG laser capsulotomy, a significant correlation was observed between PCO grading and uncorrected distance (UDVA), intermediate (UIVA), near (UNVA) visual acuity, corrected distance VA (CDVA), DLI, and VF-14 scores (All P ​