UV-VIS analysis of eyewear

I ran my Oakley sunglasses with black Iridium lenses, Tomahawk safety glasses and King's safety glasses through a UV-VIS machine to see if they absorb UV light.
The 3 glasses are remarkably similar. The curves of the 2 safety glasses are nearly superimposed on each other. The shapes of the 3 curves are so similar that I think they are made of the same material. They all absorb strongly at 370 nm, meaning they protect from UV light. The Oakley sunglasses start absorbing slightly earlier - at 396 nm, in accordance with their claims that the glasses absorb hazardous blue light. The safety glasses do not absorb in the visible region, which is why they are transparent. The sunglasses absorb slightly in the visible region. Surprisingly, they do not absorb uniformly, meaning they should result in a colour cast.