Well, they’re coated with a special chemical film that helps to filter glare for us. By having this kind of coating on polarized sunglasses, you are able to see more clearly, moreover, it helps to reduce harmful effects from UV light.
If you wear polarized sunglasses, you can have better experience in your road trips and boating. This kind of lenses absorb horizontal light waves, while still allowing vertical waves to pass through. Basically light only travels in one direction through polarized lenses which then eliminates glare.