1. What are photochromic lenses?Photochromic lenses are also referred to as light-sensitive lenses". Glass lenses are adding silver halide, but now is the mainstream of photochromic resin lenses, adding of spiro and other chemicals in the acrylic resin lens, so that the original colorless and transparent lenses. in bright light, will become colored lenses, to do the protection, so is suitable for indoor and outdoor use. Photochromic lens optical glass containing silver halide microcrystals, phototropy reversible reaction according to the principle, in the sunlight and UV irradiation variable dark, completely absorb ultraviolet and visible light absorption of neutral; back to the dark, can restore the colorless transparent. Photochromic lenses are mainly used in open-air fields, snow fields and indoor light sources, so as to prevent sunlight and ultraviolet light from damaging the eyes. Reading glasses, also known as reading glasses, are a type of optical products used for people with presbyopia. They are convex lenses. Reading glasses are mainly to meet the needs of people with presbyopia. It is no exaggeration to say that reading glasses are everyone's second eyes when they enter middle age. The use of reading glasses plays an indispensable role in improving people's quality of life. Presbyopic degrees are related to age. 2. Test discoloration? it is recommended to test at noon, noon sun UV strong, discoloration can achieve the best results, more test several times, the effect is better. Warm tipsPlease correctly understand photochromic glasses, he color depth does not equal sunglasses.