P-UV offers complete 360° UV protection. This treatment is applied to the back side of the lens, allowing to shield not only 100% of the UV rays that hits the front side of the lens, but also 95% of those that would normally be reflected by the internal surface. In conditions where sunlight comes from behind us, traditional anti-reflective treatments reflect part of the UV rays directly into our eyes. P-UV prevents this from happening by protecting us from UV rays from whatever direction they come from.
If we look towards the sun, traditional lenses without P-UV can protect us effectively. But if sunlight comes from our shoulders, traditional lenses reflect the radiation back into our eyes.