Probably could get moisture or fogged though it hasn't, but you don't actually have to focus on an image so you could probably still see your dot lined up. Most important thing is that it is set to "your" natural anchor. If I close my eyes and draw and relax my grip (no torque), in theory if it is set correctly, when I open my eyes, the anchor sight should be lined up and all I have to do is look at the right pin. It probably helps most when target shooting to keep your form the same with every shot. When you get your shot in the woods, everything should feel natural...just draw, set anchor, relax grip, double check that you are lined up, line up your pin, pull the trigger, follow shot all the way to target.
If I forget the "double check that you are lined up" it should still hit where pin is hovering. The closer the shot, the less likely you have to double check, the farther the shot, the more likely you are to think through your sequence.