Haha, it is useful to know the parts of the sunglasses, especially when some parts o sunglasses are damaged under certain circumstances. If we know the names of the parts, we can describe the problem effectively. Besides what mentioned above by the first guy, temples are the stuffs that go over our ears and hold them in place. At the end of the temple it is the temple tips. The Bridge is the metal or plastic portion that follows the curve of your nose. The sweat bar is the topmost bar. It sits above the bridge. The eye wires or rims are what hold the lenses in. End Piece, hinges and crews can help hold our temples onto the rest of our frame.
The parts of sunglasses include: lens, frame eye wires, bridge, nose pad, sweat bar, hinge, temple, end piece, temple tip. I can just recognize some of them. I will tell you what I know. First and the most important one is the lens, I think you know the function too. They help correct our vision problems or prevent the damages of UV light. And the nose pads just set between two lenses. They are used to make us feel softer and easier on your nose. But not all sunglasses must have nose pads.