To study the 360-degree barrier effect of an intraocular lens (IOL) with a square edge at the optic and an enhanced square edge at the optic-haptic junctions (Rayner 570C C-flex) on centripetal migration of lens epithelial cells (LECs) over a 2-year period.Department of Ophthalmology, Scarborough Hospital, Scarborough, United Kingdom.In a prospective study of 40 consecutive eyes, a C-flex IOL was implanted in the bag after phacoemulsification surgery. Eyes with intraoperative complications, requiring additional procedures, without 360-degree overlap of the optic, or with capsule block syndrome were excluded. Follow-up was at 6, 10, 18, and 24 months. At each visit, high-magnification retroillumination digital photographs were taken using a slitlamp-attached digital camera. The barrier effect to LEC migration across the optic edge and the enhanced square edge at the optic-haptic junction was graded as complete (no epithelial pearls or sheet), partial (few epithelial pearls without sheet), and minimal/none (epithelial sheet behind the IOL optic).Twenty-four patients came to the final follow-up at 24 months. Fifteen of these eyes (63%) had a complete barrier effect throughout the 360 degrees of the IOL. Three eyes (13%) had a partial barrier effect throughout the 360 degrees of the IOL. Three eyes had a complete optic barrier effect but a partial optic-haptic junction barrier effect. Three eyes had a partial optic barrier effect but a complete optic-haptic junction barrier effect. No eye had epithelial sheets extending behind the optic at any location.This study showed the barrier effect of the edge design of the C-flex IOL and the efficacy of the enhanced edge in preventing LEC migration at the optic-haptic junction. The enhanced edge was as effective as a sharp square edge in restricting the LEC migration.