Glasses are a total racket. Purchasing your glasses online is many, many times cheaper than going to Lenscrafters or basically any other brick & mortar store in the US. I've been buying online for years and they're every bit as good as usual ones. You do need your pupillary distance, but you either measure this yourself with the help of a friend, or ask your optometrist. If they refuse or tell you how evil buying gla…
edit: Also, one pair of glasses I ordered from Zenni gave me a rash around my eyes and on my eyelids. I've gotten contact rashes from watches before, so it wasn't entirely unexpected, but I'd never had it happen with glasses before. I thought I had just gotten a sunburn at first, and it took me a while to convince myself it was my glasses. (I basically didn't wear the glasses for a month, and then wore them again.) It's either the plastic used for the frame, or maybe a mold release. Regardless, I've tried washing the glasses with a strong detergent, and I've had them ultrasonically cleaned and they still give me a rash. They cost $30 though, which basically makes them disposable compared to normal glasses.