(1): The gray lens can absorb any color spectrum evenly, so the scene will only become darker, but there will be no obvious chromatic aberration, showing a real and natural feeling. It belongs to the neutral color system.

　　 (2): Filters out a large amount of blue light, which can improve visual contrast and clarity. It is better to wear under severe air pollution or foggy conditions. Generally, it can block the reflected light from a smooth and bright surface, and the wearer can still see the subtle parts. It is an ideal choice for drivers.

　　 (3): While absorbing light, it maximizes the green light reaching the eyes, so it has a cool and comfortable feeling, suitable for people who are prone to eye fatigue.

　　 (4): Similar to the gray lens, it belongs to the neutral lens, but the color is deeper and the visible light absorption rate is higher.

　　 (5): The lens surface adopts high-density mirror coating. Such lenses absorb more reflected visible light and are suitable for outdoor sports people.

　　(6) Yellow lens: Strictly speaking, this type of lens is not a sunglass lens, because it hardly reduces visible light, but in foggy and dusk, yellow lens can Improve contrast and provide more accurate vision, so it is also called night vision goggles. Some young people wear 'sunglasses' with yellow lenses as decoration.

　　 (7) Light blue, light pink and other lenses: the same lenses are more decorative than practical.

　　 (8): It absorbs the heat and brings a cool feeling, but the light transmittance and clarity are low. It is suitable for wearing optical lenses while in the sun, but not for driving. .

　　 (9) Blue lens: Sun blue lens can be worn when playing on the beach and beach. The blue color can effectively filter out the light blue reflected by the sea and sky. We should avoid using blue lenses when driving, because it will make us unable to distinguish the color of the traffic signal.

　　Anti-fouling film (top film)

　　(1) Principle

　　 After the surface of the lens is coated with multiple layers of anti-reflection coating, the lens is particularly prone to stains, and the stains will destroy the anti-reflection effect of the anti-reflection coating. Under the microscope, we can find that the anti-reflective coating has a porous structure, so oil stains are particularly prone to infiltrate the anti-reflective coating. The solution is to coat the top film with oil and water resistance on the anti-reflection film layer, and this film must be very thin focusing lens, so that it will not change the optical performance of the anti-reflection film.

　　(2) Process

　　The material of the antifouling film is mainly fluoride. There are two processing methods, one One is the immersion method, the other is vacuum coating, and the most common method is vacuum coating. The most commonly used method is vacuum coating. After the anti-reflective film is completed, the fluoride can be plated on the reflective film using an evaporation process. The anti-fouling film can cover the porous anti-reflection film, and can reduce the contact area of u200bu200bwater and oil with the lens, so that the oil and water droplets are not easy to adhere to the surface of the lens, so it is also called a waterproof film.

　　 For organic lenses, the ideal surface system treatment should be a composite film including anti-wear film, multilayer anti-reflection film and top film anti-fouling film. Generally, the anti-aspheric mirror wear film is the thickest, about 3-5mm, the thickness of the multilayer anti-reflection film is about 0.3um, and the top anti-fouling wax is the thinnest, about 0.005-0.01mm.

　　Take the French Essilor Crizal, composite film as an example, the lens base is first coated with a wear-resistant film with organic silicon; Then use IPC technology to perform pre-cleaning before plating anti-reflection coating with ion bombardment;

　　 After cleaning, use high-hardness zirconium dioxide (ZrO2) and other materials for multilayer Vacuum plating of the anti-reflection film; finally, a top film with a contact angle of 110 is plated. The successful development of the diamond crystal composite film technology shows that the surface treatment technology of the organic lens has reached a new level.