I know this has been beaten to death in previous posts, but today I tred a solution for visor fogging and it worked. I thought I'd share it.
First I tried Windex Anti Fog = useless.
Then I had heard of using furniture polish = it didn't work for me.
I even tried another suggestion of WD40 = again no luck.
Today I went to Lordco and was going to buy some other stuff. I asked the clerk if it was any good and he asked me what it was going to be used on. I told him of my helmet visor.
Well, rather than take my $9 for this stuff he said "Why don't you try dish liquid?".
Hmmm, OK, I never tried it, so rather than part with $9 so fast, I'll give it a whirl.
I came home and put 1 drop on a piece of tissue and rubbed it onto the inside of my visor. I kept rubbing it in until the greasy sTreaks werE gone. I went for a ride and to my surprise - IT WORKED!!
How much does one single drop of Sunlight dish liquid cost??
Suggestion - you shouldn't need more than 1 drop or you'll need to keep polishing until the greasy appearance is gone (more work than necessary). Resisit the urge to turn the tissue over and over until you rub all the solution off. With only 1 drop, you may not even need to turn the tissue over at all. And yet I had no streaky or smeary vision either. I rode all day with my visor shut. It was 95% better than no treatment at all.
Let us know if this works for you.