As with clothing, I know it's best to go into the store and try things on. But just as with clothing, I know I probably have a 1% return rate for online purchases, usually because I do my homework. Does anyone know if there's a proper way to figure out what sunglasses "probably" fit you? I know the three sizes are temple length, bridge width, and eye size and they are all measured in millimeters. I could measure some of my better fitting pairs and try to get glasses that are around that range, but how much room for play is there? Are there a set number of "ranges"? Like maybe small, medium, large where if you get a pair a few mm's off in any measurement, it'll still probably fit you? I assume there must be because some brands only make one size fits all (or at least most). Thanks.