Actually, you need to be able to try them on to ensure that you get your OC (optical center) correct. This isn't a problem for people with relatively low presc

Actually, you need to be able to try them on to ensure that you get your OC (optical center) correct. This isn't a problem for people with relatively low prescriptions, but the stronger your prescription, the more important it is to get this right. Some online stores will try to get it from a photo, but your OC actually changes by how/where you wear your glasses along the bridge of your nose, and that in turn changes with the frame you wear. So if you've got a low prescription, why not just go to the local pharmacy? They sell prescriptions as strong as +/- 3.5 over the counter for $15.