If you are shopping for prescription glasses for shooting sports, you should always buy from reputable dealer or directly from the manufacturers of these products. This is because some outfits might want to pass off inferior quality glasses as genuine products. To ensure you get top quality all the time, you should contact people who use these glasses to recommend their sources to you. You can also search for reputable firms online and buy the glasses only if you have evidence that what you are buying is the right one.
If you have offline dealers near your area, it makes sense to visit their stores and see things for yourself before you buy anything from them. Finally, you should do a bit of window-shopping before you buy these glasses. This way, you have an idea of the prices so that you avoid paying outrageous prices for them.