At present, optical experts have analyzed that the types of spectacle lenses are roughly divided into five types: anti-reflective protective lenses, colored lenses, painted lenses, polarized lenses and color-changing lenses.

1. Anti-reflective protective lens This kind of spectacle lens is coated with a thin layer of magnesium fluoride to prevent strong light reflection, so that you can see things more clearly and not interfere with strong light. To check if your glasses are really anti-reflective lenses, you can align the glasses with the light source. If you see a purple-green reflective, it means that there is indeed an anti-reflective protective film on the lens.
2, color lenses are also called "dyeing lenses", which is in the process of lens production, plus some chemicals, so that the lens color, to absorb light of a specific wavelength. This is the type of lens that sunglasses use more often.
3, coloring lens This kind of spectacle lens presents the same effect as the colored lens, only in the different way, it is the color applied to the surface of the lens, more commonly known as the "gradient color coating lens", the color is The top is deeper, then it goes down. Generally, sunglasses with degrees are mostly processed by coloring.
4. Polarized lenses In order to filter the glare of the sun in the equal direction on the surface of the water, land or snow, a vertical special coating is added to the lens, which is called a polarized lens. It is more suitable for outdoor sports (for example: sea activities, skiing or fishing).
5, color lens is also known as "photosensitive lens." Because the silver halide chemical is added to the lens, the original transparent and colorless lens will become a colored lens when it is exposed to strong light, so it is suitable for indoor and outdoor use.