First of all, nobody (certainly not me) is "yelling." I find the way you wrote this response a bit telling, and that sort of thing actually detracts from your ability to persuade.

I'd freely grant your point about the zyl. But the rest of your response is somewhat motte-and-bailey fallacy to me. For instance, I never maintained that there are "low quality plastic lens blanks." What I was getting at is that for a lot of consumers, the polarized Bausch & Lomb glass lenses are superior in quality and a better experience than the cheap plastic lenses. I also never, at any point, maintained that I'd "expect high-quality prescription lenses from a frame manufacturer." My comment was framed (pun intended) in terms of off-the-rack, non-Rx sunglasses which was absolutely clear from what I said above.

And your claim about the hinges is simply laughable. I'd dare you to stress-test (in the R&D sense) the old five-barrel bolted hinges against these cheap spring hinges. That's a Pepsi challenge I'd be willing to take any day. Incidentally, as I mentioned above, I have a pair of 1984 Ray-Ban Wayfarer IIs that are a few months away from being exactly 40 years old, and as I said they look and function like new even though they've been worn constantly for decades. Trying to maintain that the spring hinges Luxottica uses on today's Ray-Ban branded sunglasses are "high quality" completely destroys the force of your argument.