My pal already sent me links to special grinding disks etc. He's so helpful (no irony) that he sometimes totally overwhelms me . Diane, I also wear glasses, but I don't want to damage my lenses, either. They are too expensive for that. I once managed to catch a scratch to one of my lenses and my optician was speechless because he said he'd never seen that before in that particular kind. Not taking chances. I'll have to order them online, though.
Cat, I wonder if one of those grinders made for keeping dogs toenails short would work. It would be less intimidating than the dremel, but still might get the job done.
Another thing you might try if the buttons are metal is to use a pair of cutters to cut the loops off and then smooth the resulting sharp edges with sand paper or an emory board. You'd need something bigger and more sturdy than your jewelry cutters though. Back to the hardware store! I've done that with buttons before and it worked well.