This is a retrospective cohort study. Data of all patients treated at the hospital from June 1997 to October 2015 for a complication after IOL implantation will be obtained from an electronic medical record and database (FileMaker Inc., v3 - 6 and EyMed). Additional data, e.g. axial length (AL) or diopters of the implanted IOL, are taken from the patients' medical files. Collected data are age, sex, laterality of the eye, and predisposing eye conditions (PXF, relevant myopia defined as ≥ 25.5 mm axial length, uveitis, RP and ocular trauma). Other parameters are preoperative surgical interventions, the use of a capsular tension ring (CTR), perioperative complications, diopters of the IOL, pre- and postoperative corrected distance visual acuity (CDVA) in logMAR, and post-operative manifest refraction. Time to dislocation, additional interventions after cataract surgery, and symptoms due to the IOL complication will recorded. Type of dislocation (in-the-bag or out-of-the-bag), location (anterior chamber, pupillary plane or vitreous), pre- and post-operative CDVA, pre- and post-operative manifest refraction, type of secondary intervention, and in case secondary implantation was performed, type of secondary IOL are collected.