So I get situated up in my treestand, take my scope caps off and look through my scope and the lower 3rd is distorted. I cleaned glass but no change. After hunting I stop by my brothers and we shine a light and there appears to be a bubble in lower 3rd area of front lens. I come home ready to take scope off but after checking it bubble is now gone!! I said, okay must be tempature related. So I sat gun back out in cold for an hour, still no bubble, I sat gun in front of heater for an hour, still no bubble. Other than the few hours sitting in treestand the bubble is gone. I was guessing a seal was busted and air was getting in scope but now I can't duplicate issue. Scope is a burris fullfield 2-7x35. Hate to remove scope and start over but my luck it will be fine until the best hunting days next year and it will be unusable! What do you guys think is going on?