Dislocation of intraocular lens(IOL)is one complication of cataract extraction and posterior chamber IOL implantation. The reasons for IOL dislocation include incompletion of lens capsule cut, unevenness of capsulorhexis, break of zonules and/or posterior capsule, remain of lens cortex, capsule contraction, drag of exudate and organize strap, after cataract, trauma, etc. And the treatments for IOL dislocation include simple IOL reposition, capsular tension ring(CTR)implantation, anterior chamber IOL implantation, suspensory IOL implantation, IOL dislodgment, vitrectomy, etc.