I tried some stick ons and never had much luck with them. I like the "fishing" glasses from www.boomersintheknow.com They are UGLY, but they are polarized, and that really help in early morning rides into the east. The bifocal part is not polarized, so there is no distortion on you speedo screen. The have several other bifocal and reading sunglasses so you may find a pair you like. I got a pair of amber for dark or cloudy days, but I don't really use them much. Here in Fla we don't get a lot of overcast days. It's mostly sunny, and then it rains for 20 min.

I also have another pair from some company in GA. They are bifocal safety glasses that are issued by my brother in laws company. They are not polarized, but they are better looking, and the bifocal part is not as obvious. When we visit them this summer I'm going to get another pair or two, and jot down the company's name and address.