Originally Posted by
Leisesturm
Rain-X (for car windshields) has an anti-fog product. A bottle (~$5.00) will last a 30 y.o. the rest of his/her life. I use it on the inside of the $3.00 un-vented safety goggles I got from Home Depot. Home Depot also has safety glasses that fit over prescription glasses. They don't need venting because they don't close in around your eyes. They can still fog and the Rain-X will work. You can just about perceive some blurring after a time in the cold and wet but nothing like the total whiteout condition that you get without any kind of anti-fog on your lenses.
H
If you're using cheap glasses, Rain-X is ok, but it does irritate some people's eyes, and it causes the plastic to get brittle. I use
Blaze Anti-Fog on anything with plastic lenses. It's specifically formulated for plastic (Rain-X is formulated for glass). Blaze doesn't last long, and has to be re-applied every couple days, but it doesn't irritate my eyes at all, and it should make the plastic brittle or haze. I use it on all my glasses for motorcycling and bicycling, and my MC helmet visors.