If shooting indoors you should double up, both plugs and muffs. I like the Howard Leight "Leightnings" (NRR 31 $20-$25). I also have glasses and tend to just wear them as safety glasses but if you want a pair of perscription lenses specifically for shooting try one of these online sites that offer cheap (starting under $20 and up) glasses:
http://zennioptical.com/
http://www.39dollarglasses.com/
http://www.goggles4u.com/
Since they're for shooting safety and not style, just buy the ones with the largest and most protective lenses... and wrap-around frames if you're really concerned.