This is for self-defense. Not that I live in a country where they (officially) ship, but just in case...

Regarding "how to tell them apart from regular glasses", this question is mainly about Ray-Ban Blayzer Optics:

Ray-Ban Scriber Optics:

And Ray-Ban Display:

Because these are by far the hardest to identify. Other glasses either have a clearly visible "RayBan" text in the top left corner (which for the pictured ones isn't clearly visible) or can be identified just by their style.