[JJ_SO]

I think you will find aspheric elements are "concentrically ground" ...... that is why we have been seeing more onion rings in specular high-lights recently ..... it's that that leaves the concentric ridges that have to be polished out ......

Possibly I will find that, too. But I had Sigma's 14/1.8 in mind, and this is what the company says about it's front-element:

Featuring a large-diameter aspherical lens element

The SIGMA 12-24mmF4 DG HSM | Art was the first SIGMA lens to feature a large ø80mm aspherical lens element. Building on the expertise derived from this success, the new lens features a large ⌀80mm precision-molded glass aspherical lens as its front element. This technology has made possible the 14mm F1.8 specification—the first of its kind.

As far as I know, it doesn't show onion ring bokeh. I really would like to take part of a guided tour in Aizu. Except a short visit at Zeiss Oberkochen to check a Planar lens, I've never been in a place where these things are made.