Design Trivia  

I asked
about them at an opticician's place once, and was shown a catalog -- sorry I can't recall the name. They're out there; other architects have worn these as well, possibly in imitation of/homage to Le Corbusier ?
If you describe them to your optician, I'll bet he/she can produce a source. . .

SDR-
That makes sense. They probably have different "names" depending on the manufacturer. I will have to go to a lenscrafters or something and see what they can dig up for me. Make them do the work.

..
Not everyone will have a resource, but you'll find it. It may have been a French maker. . . and there are differences between "portholes," from decade to decade. I recall there were other colors besides black [but NOT for architects, I trust !].