Due to skin excretes an oily mixture that make your metal frames slippery and dirty. To prevent this grime to prevent damage to your glasses, you should wash your glasses weekly. Firstly, let your metal frames sit oversight in a glass of lukewarm water with dish soap. The dish soap will break down oil and grease from your skin, whereas hand soap may not. This step is important as it removes dust and grime as well as body oils, all of which combined can result in scratches on your lenses. After you remove your soaked lenses, rinse them in warm water to flush away the broken-down grime. You can then dry them with a soft towel. Do not use a paper towel or tissue, as they tear apart and leave fibers on your lenses. Make sure the towel is clean and as soft as possible. Special eye-cleansing cloths are available at most pharmacies or shopping centers and are relatively cheap.
I can see that you are going to figure out ways to make your frame like a new one. So, my advice for you here is to clear the dust on it, then wash it with hot water which is able to wipe away some hard tainted spots. Then, better yet, you can use some eye solution to wash it. Also, if you have some tools , you could even have the frame polished. Or perhaps you can paint them with new paints.
Well, to clean the metal eyeglasses, you should follow some steps. For example, if the lens is merely dirty and not covered in abundant grease and grim, you can use a good quality linen or cotton cloth which will work wonders. Then, you can also use some resolution to clean it one more time. For the surface of the nose pad and the metal frames, you can also soak them for a couple of hours in warm water to loosen the residue. Then it will be easy to gently brush away the unwanted dirt with an old soft bristle brush or old toothbrush. Anyway, you should do the entire task in a gentle way so that you will not damage your glasses.