Abstract: Phacoemulsification cataract extraction and intraocular lens (IOL) implantation is the most effective method for cataract patients. As the implanted biomaterials, IOL can initiate a series of biological reactions. IOL biocompatibility evaluation follows two major principles, which are bio-safety and bio-function principles. Biosafety evaluation includes cytotoxicity tests, genetic toxicity tests, irritation and sensitization test, as well as implantation test. Biofunction evaluation includes the evaluations of uveal biocompatibility and capsular biocompatibility.