If its the yellow looking film, peel it off. Its just a protective film.
The Sierra's have a dual pane lens system, that's doing most of the work to prevent you from fogging up too much. I'd recommend applying some additional anti-fog solution on the inner lens though. While they're highly fog resistant in my experience, they still can fog up after a good few hours of running around.
Just your friendly neighborhood narcissist gearwhore.
Last edited by beta678; November 13th, 2015 at 17:28..