TAC POLARIZED LENS- 100% UV400 protection coating, blocks 100% harmful UVA,UVB& UVC Rays. Restore vivid color, eliminate reflected light and scattered light and protect eyes perfectly. TAC lens includes 8 layers. The 1st layer is polarization layer. The 2nd and 3rd layers are adhesive layers to enable durability. The 4th and 5th layers are UV protection layers to absorb UV light. The 6th and 7th layers are shatterproof layers.The 8th layers are anti reflective green coating. STRONG STURDY DURABLE- Metal clip ends with silicone sock to provide LONG LASTING durability and avoid scratch your lens.It fits precisely over prescription glasses for man to wear it in summer, or outdoor activity like cycling bicycle, driving, riding a motorcycle,running,fishing, racing, skiing, climbing, trekking etc. LIFETIME BREAKAGE WARRANTY ON FRAME & LENS - Frame and lens are unbreakable for no risk purchasing. In case any broken problem happens for any reason, even you stepped on it by accident, contact the seller of Joopin to get a new replacement.Joopin provides lifetime service for all Joopin products. 30 DAY MONEY BACK GUARANTEE- You can easy return and get refunded for any reason like I don't like the style,I don't like the color,etc. Don't worry,You have no risk to try. How Do Polarized Lenses Work? Light reflected from surfaces such as a flat road or smooth water generally is horizontally polarized. This means that, instead of light being scattered in all directions in more usual ways, reflected light generally travels in a more horizontally oriented direction. This creates an annoying and sometimes dangerous intensity of light that we experience as glare. Polarized sunglasses reduce glare reflected off of roads, bodies of water, snow, and other horizontal surfaces. Polarized sunglasses cut glare and haze so your eyes are more comfortable and you can see better.