The last time I had an eye exam, I just bought new lenses for my frames. My frames were still in good shape, so I figured, why not? I loved the style and it will save some money.
Wouldn't you know it - the frames broke right on the side of the bridge a few months later. The frames are titanium, and no one could sauder them back together. (NOTE ADDED 5/6/05 - someone left a great comment on this post mentioning that some titanium frames have a lifetime warranty. So, make sure you take your glasses back to where you purchased them from and ask. And next time you shop for glasses, make sure that you ask about any warranties - they could save you some money down the road)
As I wondered what to do, because at the time I was not working and income was super tight - I had an idea. What about using a pair of sunglasses? It turned out that I had an old pair that looked like they would almost work. So I got out a pair of pliers and started shaping the sunglasses in the shape of my lenses. I placed the lenses in, and voila - I had glasses again.
To the naked eye, you can't tell they are sunglasses. They are actually quite stylish too. Just a note - this method works best with frames that only use a plastic wire for the bottom. Then you only have to shape the top of the frames :)
Total Savings - over $100.