TBH always thought these were stupid until they saved the day during a particularity strenuous hike. Out of nowhere hundreds of flying bugs swarmed our faces, they didn't bite or sting but they were crawling in our noses, ears, mouth, eyes pretty much anywhere they could to the point it was hard to breathe. It was torture UNTIL we popped one of these on! They were still swarming but they couldn't get all up in us.
Flash forward a few months and now the epic face protector is used daily.