Comment by somat

With regards to the first one described the TDK with the UV guard, I am curious as to what that is. My guess is it has more to do with avoiding UV related damage than blocking UV.

I am not sure the authors spectrometer test(which was very cool, avidly reading that series of articles right now) would reveal anything as polycarbonate is naturally quite opaque to uv light.

https://en.wikipedia.org/wiki/Polycarbonate#/media/File:Visi... Note how the transmission is dramatically reduced once past violet.

Fun fact ordinary clear polycarbonate eyeglasses do just as good a job as sun glasses at protecting your eyes from uv.