Two years ago I bought my daughter a pair of glasses at Sears, and they've been great for her. Cute frames, and she's satisified with the lenses. The price was certainly right: It's been a while, but they were less than $100.
She was so satisfied that I went to Sears when I needed glasses again. My more complicated bifocal lenses were considerably more expensive (I want to say $250, but it's been a while), and they explained that my daughter'd got such a great deal because she was under 16 -- they always have that deal for kids. I'm not so satisfied with my Sears glasses. The coating is starting to be weird -- it's not coming off, but there are some ever-so-slight "spots", which I notice occasionally. I've been wearing glasses since I was 14, and I've never had anything like this on any other pair.
All in all, I probably will not return to Sears.
I've ordered from Zenni too. I ordered a pair of prescription sunglasses, and I was very, very dissatisifed. The legs of the frames were too short, and they hurt my ears. The lenses were great, but I couldn't bear to wear them for more than a few minutes at a time. Even at $10 or so, it was a total waste.