We “discovered” this 2011 Discovery Channel video on how lenses are made. (The video refers to “television” lenses and the lenses are from JML Optical.) Though there are lots of marketing videos out there promoting this or that brand lens, they do not really educate much. This video, on the other hand, is more technical and gives an eye-opening explanation of how camera lenses are made, including the all-important electron-beam coating.
It seems to be a very manual endeavor and I wonder if it’s not much more automated these days. Anyways, it is very dependent on the people grinding the glass, polishing it and assembling it to make the finished product. After watching this video, it makes you want to handle your lens with a little bit more care, doesn’t it?