AIM: To evaluate the effect of lens surgery on health-related quality of life (HRQoL) of preschool children with congenital ectopia lentis (CEL). METHODS: A prospective self-controlled study was conducted in Zhongshan Ophthalmic Center. Children aged from 5 to 7y whom were diagnosed with CEL and underwent phacoemulsification with scleral-fixated posterior chamber intraocular lens implantation and their parents were enrolled in this study. All of them completed the child and proxy (parental) PedsQL™ 4.0 before and after the surgery. Their preoperative scores were compared to their postoperative ones. Subgroup analyses were performed based on gender and preoperative bilateral presenting visual acuity of the children. RESULTS: Thirty-two children with CEL successfully underwent surgery without any complications, among whom 8 had monocular surgery and 24 had binocular surgery. Preoperative and postoperative questionnaires were completed by 32 child-parent pairs. Surgical intervention could significantly improve the vision of affected children (P<0.001). The medians of physical, psychosocial and total health scores self-reported by the children were 68.75 (62.50, 81.25), 65.00 (60.00, 80.00) and 67.39 (60.87, 78.26) preoperatively and were 93.75 (87.50, 100.00), 90.00 (83.33, 96.67) and 89.13 (85.32, 95.65) postoperatively. The preoperative scores of the affected children were significantly lower in all scales than age-matched healthy children (P<0.001). All the postoperative scores were significantly higher than the preoperative scores in affected children and their parents (P<0.001). In the physical functioning evaluation, the preoperative score reported by parents of girls was higher than parents of boys (P=0.041), and the postoperative score of girls was higher than that of boys (P=0.036). CONCLUSION: CEL is associated with significantly worse quality of life in preschool children. Surgical intervention can significantly improve the HRQoL in affected children from both personal and family perspective.