I've bought three pairs of glasses from Zenni. The arm snapped off of my last pair. After that I bought two pair. At $30 each shipped, it's still worth it. The current pair I wear are comfortable and fairly strong (they withstand the beating my twin daughters give them).
The issue with Zenni (and others where the lenses are produced outside the country) is they don't have the stringent quality control standards for lenses you find in the US, Canada and Europe.
If you have a fairly common and simple prescription, go for it. If you need progressives or bifocals, you should probably avoid buying online.
I agree, and I generally get a couple of pairs from Zenni whenever I order for that reason (my toddler and my cat both like to knock the glasses off my face for a laugh). I haven't noticed that the quality of Zenni's lenses is worse than, say, Lenscrafters or any of the other "1-hour" shops here in the US. I like the try before you buy idea of WP, but they really don't have a lot of options (dig the monocle, though).
The issue with Zenni (and others where the lenses are produced outside the country) is they don't have the stringent quality control standards for lenses you find in the US, Canada and Europe.
If you have a fairly common and simple prescription, go for it. If you need progressives or bifocals, you should probably avoid buying online.