But those remarks are just the lens. The lens came out out the 3D printer with a frosty surface. Of course that needs polishing. No 3D printer is going to crank out working optics.
What is surprising here is that the object has the internal clarity, so that all it needs is a surface polish. I imagine it must be relatively free of voids and inclusions.
I have used 3d printed molds to help me create lenses, but the idea of actually printing a lens is pretty gnarly. I think it definitely qualifies as 3d printing - most models require some touchups after printing from consumer printers anyway.
What is surprising here is that the object has the internal clarity, so that all it needs is a surface polish. I imagine it must be relatively free of voids and inclusions.