Local stores would always be short of the frames you need. Your requirement would be different from what is made available in store. While the proximity as well as look and feel could be experienced by you when you look at the frames in real you may have questions about the quality of material versus the price mentioned by the store seller. Since it is related to eyes you may not want to do comparison like you do to buy a mobile on online stores. However, this would be the best way to know the facts about the price versus material quality. Why does a metal frame cost you more or why does a style of a frame could cost you less would all be clearly understood by you when you shop online.
One other concern is about the prescription-based eyeglasses that you should use. While the frame selection could be done by you, the eyeglasses should be inline with the prescription. When there is a feasibility for you to upload the prescription, there is nothing else that could stop you from getting the cheap eyeglasses online. For a person who is buying the eyeglasses for the first time there will be many questions that are simple. The online professionals would be ready to answer every question that their visitors have and hence you could feel free to ask any question.
The questions could also be related to the material to be selected for the lifetime of the frame and the eyeglasses. You could also check if the frame could remain the same by any chance if the prescription changes and you could only get the eyeglasses replaced. All such questions would be answered post which your order will be served satisfying you to the best of their knowledge.