This place is great. Sadly I am on my third trip here in as many months (kids lose glasses ALL THE TIME), but they have the prescription on file, as well as the frame my kiddo likes.
Buying here is cost effective. The first pair we bought our daughter at the ophthalmologist's office cost over $200 (and that is with insurance and glasses allowance). Each pair I've bought here is around $50 (and that is only because I get the scratch coating and have to rush the shipping).
Great staff, good selection. Highly recommend.