I used to buy eyeglasses from eyebuydirect.com, but had to go elsewhere as ther didn't go to -6.5 at that time. I have been using Zenni and Goggles4you quite joyfully as well.
Online cheap glasses are great. I've gotten one "bad" pair in 20 years, which was successfully replaced at no charge. My prescription will cost me about $400 at Lenscrafters, but online I can get glasses AND sunglasses for about $125.