I second using Zenni Optical. Glasses are cheap enough that you can almost consider them disposable. I get the memory titanium frames (~$13) and bifocals and they're still <$50/pair. The pair I have on are > 1 year old and despite daily wear are almost like new. Some of my acquaintance have bought the plastic frames and been very disappointed in the durability. I have several spare pairs for the car,in my BOB,at the office, etc and have less invested than most places charge for a single pair.