polarized sunglasses

Wearing polarized sunglasses may occur this problem.

The lens coating can solve this problem.

A common problem with refractive glasses and sunglasses is glare. Back glare is the light to the back of the lens, and reflected to your eyes. The anti-reflective (AR) coating (anti-reflective coating) serves to reduce this reflection of light to the lens. In bad cases, you may even see the mirror of your eyes in the lens. Similar to the scratch-resistant coating, the AR coating is also a very thin film applied to the lens. The refractive index of the anti-reflective protective coating material is between air and glass. This makes the intensity of the reflected light on the inner and outer surfaces of the film almost equal. When the thickness of the film is about a quarter of the wavelength of the light, the light reflected from the inner and outer surfaces of the film will cancel each other by canceling the interference, thereby minimizing the glare you see. Anti-reflective protective coating is also applied to the front surface of refractive contact lenses and some sunglasses to eliminate the hot spots generated by the lens's reflection of light.