This doesn't work as an explanation, lenses are always cut to the frame.
My brother in law owned a lens cutting shop and they have boxes filled with lenses ground to all sorts of prescriptions that are circular plugs 3 or 4 inches in diameter. When the order comes in they use the pupil measurements and the frames to cut the lenses for the prescription down to fit into the frame.
My brother in law owned a lens cutting shop and they have boxes filled with lenses ground to all sorts of prescriptions that are circular plugs 3 or 4 inches in diameter. When the order comes in they use the pupil measurements and the frames to cut the lenses for the prescription down to fit into the frame.
I don't know how well I explained that but you can watch this video to see exactly how it works: https://www.youtube.com/watch?v=uCjGNUPO0WU