I have a pair of Liquid Polarized prescription sunglasses that are awesome to ride with. The ones I have are called, "Gaskets". I'm a big guy(6'-3", 300lbs)and they fit my big ol' head pretty good. I also ordered the prescription insert for them as well. I've never experienced any problems whatsoever with the glasses or the rx lenses. No distortion like you normally get from wraparound rx glasses. These are by far, the best glasses I've ever owned.
You'll have to get your rx from an eye doctor and send it to Liquid, then they'll make the insert. I've had mine for about a year or so and absolutely love them. I ordered mine with LTD (light-to-dark, similar to transitions) lenses.
The insert snaps inside the sunglass lens, and feels really comfortable. Contact them, and ask for Kristen, she's really helpful. But I'll warn you... these aren't the WalMart cheapies. I don't like handing over my dough, but on some things... you just have to.
Here's a link to their site:
http://www.liquidpolarized.com/store/That being said... I'm not going to get into a long argument with some moron about spending a bunch of cash on glasses. Because I like to save a buck anywhere I can too. So don't even respond if you don't have anything positive to say. On some things you just don't get what you need unless you spend a few dollars. I know, it sucks, but I don't make the rules. But I can tell you this... on some things in life, you get what you pay for.