Don't you think that if people had purchased crappy glasses from Zenni, they would have piped up? "You get what you pay for" is not always true. From what I have read and experienced, glasses from Zenni have held up.

While I agree that it is extremely important to get the right measurements from an optometrist, I think that it's a fallacy that the quality of glasses is higher.

http://www.cheatsheet.com/gear-style/worth-buy-expensive-glasses.html/?a=viewall

I was reading a thread on reddit the other day and the topic was things that things that are generally too expensive for what you get. One of the top responses was eyeglasses and the top response under that was all about Zenni. I didn't see one comment about glasses from Zenni being cheap. Everyone was talking about how they got 3-5 pairs for what it would have costed at the optometrist and that they were happy with the quality.

I also found this thread full of good info
https://www.reddit.com/r/YouShouldKnow/comments/2j81m1/ysk_that_eyeglasses_are_heavily_marked_up_in/