go to the cheap rack at the indy or dealer or swap meet and keep putting them on till you find one that fits and feels good and if it has foam or the rubber its going to be even better and keep about everything out.
I bought harley profile glasses.they work best for me.the foam around the frame,plus the string to tighten them flush against my face seals the wind out. I wear a contac lens in one eye ,not a problem with these glasses.
I would love to get a pair of these. Can anyone who has a pair chime in on how they fit with a helmet on? They're so big they look like they would push up on the front of your helmet.
p.s. And for those of you in the "Helmet Optional" states....bite me!