JoeRay's given the most helpful answer to your search, so I'm just adding a couple of notes based on Scott's answer.
"Discriminate" does have some negative connotations in Western culture, mainly because it's been tied to racism. I think you meant to write, "discriminate between", ie. define the differences.
Probably, your best option is "how to choose between...?" or "how to decide between..?"
"Glasses" (ie. eyewear for reading, or in the sun) is always plural. Two pieces of glass, you see. ;) And if you specifically mean sunglasses, then use that word. Writing "glasses" alone suggests they are reading glasses.
"How to decide between Rayban sunglasses?" is my suggestion for the wording of your question.