39 Dollar Glasses are usually, well, US$39 but now they're doing 20% off the entire range of prescription eyeglasses and sunglasses. They claim they are "the world's number 1 online optical store".
edit: Code WWMAG will you get $20 off. Better if ordering one pair.
I discovered them after OzB put up their last deal and was very happy with the glasses, the service and the great price. They are manufactured in the USA and postage took me max 10 days, costing about $15.
It's the lens coatings that are so much cheaper as well, e.g. US$25 (before 20% off) for anti-glare on clear single vision lens.
I got 2 pairs for free at Spec Savers !!!