The objective of this clinical study is to select the optimal dose and evaluate the safety and efficacy of NR082 in treatment of LHON caused by mitochondrial ND4 gene mutation. Part 1 (Phase 1/2) is a safety dose-finding study, which will enroll subjects aged ≥ 18 years old and ≤ 75 years old to receive a single unilateral intravitreal (IVT) injection of NR082 to observe its safety and efficacy. In Part 2 (Phase 3) of the clinical study, the dose recommended after the end of Part 1 is used to further verify the safety and efficacy of the study drug. Part 2 of the study is divided into the safety run-in phase and the randomized, double-blind and control study. Subjects aged ≥ 12 years and ≤ 75 years will be enrolled in the Part 2. The run-in phase will enroll 6 evaluable subjects. After monitoring for at least 6 weeks, if no new safety signals are observed, the clinical trial will enter the randomized, double-blind and control study phase upon approval by the Safety Review Committee(SRC). The clinical manifestation of all subjects is reduced visual acuity caused by LHON associated with ND4 mutation, and central laboratory test showed G11778A mutation (a CLIA-certified laboratory), while the reduced visual acuity lasted for > 6 months and < 10 years.