Intraocular lenses (IOLs), proposed as a drug delivery device, hold the potential to replace conventional eye drops and other therapies after cataract surgery, and to be used in the prevention and treatment of post-surgery complications such as postoperative infection, endophthalmitis, and posterior capsule opacities. The key advantage of drug-loaded IOLs is that they can ensure continuous drug delivery independent of patient compliance, without requiring any further operation besides IOL implantation. In this review, we summarize the research progress on the utility of IOLs as drug delivery systems, elucidating the drug loading strategies, as well as types of loaded drugs and the current state of clinical research. The review may deepen the understanding of the latest progress in this field, providing strategies and rationale for the treatment of certain eye diseases, such as intraocular inflammation and postoperative complications of cataracts.