Too late for Triskeliongirl, but one thing I wish I'd done before I ordered my expensive prescription cycling sunglasses a couple of years ago is tried them on with a bike helmet. They are actually skiing glasses but they should work fine for cycling, except they don't fit well with any of my three helmets, and I wind up with miserable pain at each temple. I wind up riding without sunglasses more often than not because they are so uncomfortable.

I just ordered new sunglasses yesterday but they are not cycling-specific; I really needed just a general pair. Transition lenses are a great idea, though, so if I ever get to the point where I can afford a new pair of cycling lenses I will do that. I should really also talk my husband into doing that, too, after the number of times I've had to go pick him up because he didn't have his regular prescription lenses with him and it got too dark for him to ride home in sunglasses!