Purpose: To clarify the extent to which the adhesiveness of an acrylic material influences the formation of posterior capsule opacification (PCO). Setting: Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan. Methods: Two types of AcrySof (R) intraocular lenses (IOLs) were prepared: round edged and tumbled. The AcrySOf With round edges was implanted in 1 eye in a group of ii rabbits and the tumbled IOL in 1 eye in a group of 5 rabbits, In both groups, the contralateral eye received a conventional AcrySof with sharp optic edges. A histopathological examination was,performed 3 weeks after surgery. Results: With the round-edged AcrySof IOL, no capsular bend formed at the optic edge and abundant lens epithelial cells (LECs) migrated posteriorly. With the sharp-edged AcrySof lens, a sharp capsular bend formed and LEC migration was significantly inhibited. In eyes with a tumbled IOL, a capsular bend was created, but it was less marked than that created by the sharp-edged lens and there was slightly more LEC migration posteriorly. Conclusions: The AcrySof IOL lost its preventive effect on PCO when the optic was rounded. The effect of the AcrySof lens in preventing PCO is mainly a result of its rectangular, sharp-edged optic design. The acrylic material may play a complementary role by helping create a sharp capsular bend. Capsular bend formation is the key to the PCO preventive effect of an IOL.