Many scientists believe that gene therapy has been most successful in the field of ophthalmology, thanks in large part to gene therapy for Leber’s congenital amaurosis. Leber’s congenital amaurosis (abbreviated LCA) is an autosomal recessive retinopathy that often develops in infancy and childhood and leads to complete blindness in adulthood. Eighteen causative genes associated with Leber’s congenital amaurosis have been identified both nationally and internationally, with mutations in the RPE65 gene, which encodes an isomerase involved in the vitamin A-like cycle in the mammalian visual pathway, being the most common. In a recent clinical study, a total of 15 patients were treated with gene therapy in which the normal RPE65 gene was loaded onto adeno-associated virus (AAV) and then injected into the subretinal space. The patients’ light sensitivity increased 200- to 60,000-fold after treatment, and 12 of them experienced significant improvement in visual acuity, with no adverse effects or complications at 3-year follow-up. This success is a ray of hope for the treatment of other hereditary eye diseases, which is still in the clinical trial stage and has not yet been officially introduced into the pharmaceutical market.