Purpose: To determine the incision size after insertion of foldable intraocular lenses (IOLs) using both a forceps and injectors. Setting: Intermountain Ocular Research Center, Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Methods: One hundred patients had phacoemulsification through a clear corneal wound. The incision width was measured before and after IOL implantation. A 3-piece silicone IOL and a 3-piece acrylic IOL (both with an optic diameter of 5.5 mm) were inserted using a forceps. A plate-haptic silicone lens and a 3-piece silicone lens with a 6.0 mm diameter optic were inserted using an injector. Results: The wound size in the group with the 3-piece silicone lens inserted with a forceps enlarged 4.4% (3.23 to 3.38 mm) in the low-power IOL group (15.0 to 20.0 diopters [D]) : and 6.2% (3.24 to 3.44 mm) in the high-power IOL group (20.5 to 25.0 D). Similarly, the acrylic IOL wound enlarged 5% (3.21 to 3.37 mm) in the low-power IOL group and 6% (3.25 to 3.44 mm) in the high-power IOL group when a forceps was used. The 3-piece silicone and plate silicone lenses inserted using an injector enlarged the wound 3.2% and 3.3% (3.02 to 3.11 mm and 3.05 to 3.15 mm), respectively. There was no difference in the wound size with higher IOL powers in eyes with injected lenses. Conclusions: Clear corneal incisions enlarge after insertion of foldable IOLs in a predictable manner, with a forceps-inserted IOL enlarging the wound diameter more than lenses inserted with an injector. The forceps-inserted lens group also showed a difference in wound size related to IOL power. (C) 2000 ASCRS and ESCRS.