In modern society, children and adolescents are experiencing an increasing incidence of myopia, resulting from the combined influence of genetic factor and environmental factor. Despite the influence of genetic factor, a great number of researches indicate that environmental factor has been playing a crucial role. Outdoor activity proves to be a major protective factor to reduce the incidence of children's myopia. Sunlight is one of the important ones among various factors of outdoor activity. The intensity, wavelength and rhythm of sunlight may all affect eyeball's refraction development. Varied sunlight environment may have different influences on eyeball's refraction development. The paper has summarized clinical and trial and animal experiment research results on how sunlight affects eyeball's refraction development, and it has offered references to further study on refractive error development mechanism and prevention strategy.