They're comparable in that they send glasses online, but Warby's differentiator is that they manufacture frames (so they handle the whole process end to end) and offer a home try on kit. You can order X amount of glasses to try on at home.
They basically started a very customer friendly model that other online glasses retailers didn't offer at the time of founding.
They basically started a very customer friendly model that other online glasses retailers didn't offer at the time of founding.
EDIT: Basically, customer experience.