Ocular drug delivery has made significant progress not just for fast developing gene therapy items but also for pharmaceutical chemicals such steroids, non-steroidal anti-inflammatory medications, immune modulators, antibiotics, and so on. While the main considerations for achieving adequate treatment outcomes for conventional non-gene therapy drugs are appropriate surgical techniques and release systems, the scope of "drug delivery" for gene therapy drugs is further expanded to include vector selection, vector engineering, and transgene construct optimization. Because it has so many benefits, the eye is an especially good organ to target with gene therapy. We will examine three key areas of ocular drug delivery in this review, pertaining to both conventional drugs and Aden-associated virus (AAV)-based gene therapy products: (1) the creation of AAV vector systems for ocular gene therapy, (2) novel drug carriers, and (3) the evolution of administration routes.