Don't forget that Coastal.com offers free eyeglasses to anyone who buys an eligible pair and enters the coupon code "FIRSTPAIRFREE" when paying. I just bought a pair for $14! Yippee!
If you don't have a current prescription, try this: look for optometrists in local malls and check their specials. They often have a flat-free promotion for exams. I got mine for under $30 in Miami... not bad at all.