AIM:To investigate related factors,prevention and treatment measures of intraocular lens(IOL)displacement or dislocation in cataract extraction and posterior chamber IOL implantation.METHODS:IOL displacement or dislocation enrolled into our hospital from February 2009 to May 2010 were retrospectively analyzed.The main record included the cataract condition,discovery time of displacement or dislocation of IOL,the symptoms and signs,treatment and visual acuity before and after treatment.RESULTS:Displacement or dislocation of lens was recorded in 27 patients with 27 eyes,among which 17 eyes were combined with other ocular diseases complicated cataract.Discovery time of displacement or dislocation was postoperative 1 day-14 years.Varying degrees of posterior capsule rupture was recorded in 12 eyes;anterior capsule tear in 5 eyes,a larger capsulorhexis in 3 eyes,small circular capsulorhexis with organized contraction and opacification of anterior capsule in 1 eye;postoperative history of ocular trauma in 6 eyes.27 patients were treated by reoperation and followed up for 10.23±2.10(3-16)months.Uncorrected visual acuity was better than that of before surgery,the difference was statistically significant(T=-0.327,P=0.001);compared with before surgery,best-corrected visual acuity after surgery was of no significant difference(T=-0.611,P=0.541).CONCLUSION:The complexity of the eye disease,posterior capsule rupture,poor anterior capsule capsulorhexis,postoperative ocular trauma are the important impact factors of displacement or dislocation of IOL.Skilled surgical technique,proper treatment of intraoperative complications are key to prevent displacement or dislocation of IOL.IOL position adjusting or suspension surgery is an effective way to deal with displaced or dislocated IOL.