Nitric oxide(NO)is an endothelial-derived relaxing factor produced by endothelial cells and catalyzed by nitric oxide synthase(NOS), which is present in many organs and tissues of the human body. NO is a key gaseous signaling molecule that mediates a variety of physiopathological processes in organisms. NO and NOS have many functions including the regulation of vascular tone, the relaxation of smooth muscle, activation of immune responses and modulation of neuro-transmission. They have been used in the treatment of diseases in a certain field. In recent years, the incidence of ophthalmic diseases has been on the rise, and the quality of life of patients has been reduced. However, treatment for most diseases is limited. It is find that NO and NOS can be detected in various tissue of ocular parts, and they are involved in the occurrence and transformation of many ocular surface and fundus diseases. This article reviews the correlation between them and ocular diseases, analyzes the mechanism and principle of the occurrence and development of diseases, and provides new ideas for the clinical treatment of ophthalmic diseases in the future.