Firstly, I love this prop and would love to try to replicate it, even if we never really fully see it on screen.
I've always had the feeling that the dome on the left was kit-bashed.
I've always viewed the tip as clear, not unlike the McCoy STVI scanner. For some reason, I've also had the impression that there is a hole in the end of that clear tip—sort of like a pocket microscope—but upon close inspection of the frames above, I see no particular evidence for that.
Perhaps there are publicity stills somewhere that give us a different view of it?