I can honestly say i was in the same boat the "i break my glasses and cheap ones work fine" boat. My girlfriend bought me Costa's (Swordfish model with the 400 lens
) I have now had them since November and will never go back. The quality of the lens is much better. A glass lens is stronger and much cleaner/clear then cheap polarized lenses. I can honestly say my eyes feel much better wearing them as far as light giving me a headache or making it harder to see once you step right into a darker place. When you have better glasses you tend to take care of them a lot more. Also with the cheapies i would only make sure i had them while going on the boat, with the costas i like them so much i make sure i have them every time i leave the house! Good luck! i also know Costas have great customer satisfaction and will fix pretty much anything for you!