The objective of this clinical study is to evaluate the safety, tolerability and preliminary efficacy of NFS-02 in the treatment of LHON caused by mitochondrial ND1 gene mutation. This study will enroll subjects aged ≥ 18 years old and ≤ 75 years old to receive a single unilateral intravitreal (IVT) injection of NFS-02 to evaluate its safety, tolerability and preliminary efficacy. The clinical manifestations of all subjects are to be reduced visual acuity caused by LHON associated with ND1 mutation, with laboratory test showing G3460A mutation (a CLIA-certified laboratory) and reduced visual acuity lasted for \> 6 months and \< 10 years.