I had the exact same problem trying to look out between the smudgy bits in my glasses. I got a bit of fabric about 20mm wide and tie it on ala ninja style.I have the same problem, it wouldn't bother me so much but for the fact that sweat runs down the inside of my glasses, meaning i need to stop and clean them all the time.
I'm keen to check out that sweatband.
Works great and its thin enough to not know its there. I tried a full on headband but it was way to bulky for my liking