If you're a system builder and someone wants one of these, just issue some free tin-foil hats and you'll be fine.
Not sure where on earth you've got this from, but just because a material does or doesn't allow light within the visible spectrum of EM radiation through, doesn't have much of a bearing on whether it does or doesn't allow potentially harmful EM radiation (e.g. the lasers from CD drives) through. CPUs, for example, probably give off radiation, but that radiation does not cause you harm.
It's a non-issue.