1, green has a role in regulating vision, more suitable for students; 2, light gray can reduce visual fatigue, eye more white-collar workers can consider; 3, yellow is the most sensitive color of the visual cells, can improve the sensitivity of vision, amblyopia and other poor vision can be preferred; 4, red-green blindness or red-green weakness, can choose red lenses, it can increase the red-green contrast; 5, blue or purple to Retina has a photodamaging effect, will reduce the field of vision, with fundus hemorrhage or macular degeneration of patients do not choose. 6, a good sunglasses should be marked with the words “uv-400”, and indicate the production brand, specifications, factory address, etc.. Sunglasses are only suitable for wearing under the hot sun, sunset, cloudy days, rainy days, indoor should not wear. 7, for patients with myopia, can choose color-changing film, also has a good protection against ultraviolet light.