Gene therapy involves replacing or altering a patient’s genetic material to achieve a therapeutic effect, typically in the context of a genetically inherited disease. Built on a long history of research dating back to the description of DNA exchange between bacteria in the 1940s, the field of gene therapy has hurtled to the forefront of medical research in recent years. Advancements in genetic sequencing, gene delivery technologies, and proof-of-principle work in cell culture and animal disease models have all culminated in human gene therapy trials across a wide range of genetic diseases, including inherited blood disorders, primary immunodeficiencies, neurodegenerative disorders, and more. While many medical disciplines are conducting ongoing investigations, ophthalmology, and in particular the field of inherited retinal diseases (IRD), leads the way with the first published phase III clinical trial and United States Food and Drug Administration (US FDA)–approved gene therapy. Table_x001F_1 summarizes ongoing gene therapy trials for ocular diseases in the US.