if you’re in to avoiding paying hyper-inflated costs to support entrenched and anticompetitive markets, like what eyeglsses have been for years, I higly recommend Zenni Optical. They have highly customizable options and are great glasses, especially for the price. http://www.zennioptical.com Edit: spelling
My best experience to date for avoiding price-gouging has actually been at Costco's in-house optical. My experience with Zenni was of the "you get what you pay for" variety.
They work fine, but it's like buying anything else designed to be disposable. Make sure you have a few pairs on hand for backup