Remember way back in early March when I posted that I had to return a pair of glasses to Zenni Optical because one lens was bad? I'd long given up even calling them to ask when they might be going to do something about that order ("A technician will have to look at those and call you back in a couple of days"). Well you could have knocked me over with a feather when I got email from Zenni with info that my order was being resubmitted. The glasses arrived today. Much better. Still not the optical quality that I'd insist on if I'd paid $380.00, but good enough, and well worth the $38.00 Zenni price.
There are still some ripples in the left lens. I think I understand what the problem is. My nearsightedness in that eye is severe enough that the relatively thin blank they start with gets almost ground away in the center. The stress from being clamped in the frame is enough to distort the center of the lens slightly. Not bad enough to be worth trying to fix at this point.