Replying to How to Clean Smith Goggle Lens

Hey guys I started noticing that every time I used my "goggle lens cleaner" in my Spyder coat my goggles would get smudged.

Now I realize that these are permanent smudges.

I have googled how to clean goggle lens but have come up with nothing.

Nobody seems to know exactly how to clean goggles, not even the manufacturers of the goggles.

So my question is: how should I clean my goggle lens? I've just been fogging them up with my breath but I'd like to get some spots off.

(*The only thing I know is NOT to use paper products or non-water liquids)