In the same boat. For my bike, I just want my distance prescription - I can see my computer well enough.
I ordered some prescription sunglasses online, and I'm very disappointed. They're heavy, ugly, and my eyelashes really hit them hard. So, I wouldn't want to try to do that again.
I want a pair that is really cycling specific to keep wind and debris out. I know Rudy Projects has some that are really nice, but they're expensive. I was hoping to get some that either transition for night riding, or have interchangeable lenses. Either way adds up!
For 3 days, I get to part of a thousand other journeys.