Originally Posted by
rogerstg
FWIW, most plastic lenses do protect from UV radiation with nothing special added, it's the nature of most plastics - even saran wrap blocks a good amount of UV.
Depends on the type of plastic, whether coating is applied to it and the wavelength of the radiation. 300 to 400 nm wavelengths go through plastic easily. UVB is from 280 to 320 nm so part of it could pass through many plastics. Altitude also has an effect also since the UV flux increases about 10% every 3000 feet.