If you say the "arms" on my glasses, everyone will know what you are saying as opposed to any other term. You can guess at what stems are, but temple is confusing if you don't know what it means in relations to glasses.
dude...i am not saying that temple is not confusing...but that is what they are called. that is the name.
and arms is no more clear then stems, and certainly not any more clear then "sides" or as many optometry histories state "side pieces"...before finally being called "temples"
History Of Eye Glasses - teagleoptometry.com
and the fact is, they are called temples, because the first pair to have the rigid sidepieces, were designed so that the sidepiece, obviously, rested against the temples, providing a firm fit...thusly the name "Temple Spectacles"...then later, came the double-hinged temple.
Eyeglasses Through the Ages
so let's just stop this nonsensical squabbling.
they are called temples, however it does not matter how one chooses to refer to them in their own vernacular, be it "Stems" "arms" or "side-thingys"