39DollarGlasses takes $20 off any purchase with no minimum required via coupon code "CM20". That's the best dollar-off discount we've seen from 39DollarGlasses this year. (We saw $17 off in September.) After discount, dozens of pairs of eyeglasses, including frames and prescription lenses, are $19 plus $4.95 for shipping.

Note: Although this coupon was supposed to expire two days ago, it's still active.