Is it possible to get sungl lenses for an existing pair of frames?

I have a pair of frames that I love. I found them at a resale shop for $2, but they're in really really good condition, I doubt they were ever worn. The lenses in them are for reading gles, which I don't need. I think they would make fabulous sungles, and I'm wondering if it's possible to find or order sungl lenses to fit them? Anyone have any idea where I could find out about this?