I think I've had this problem occasionally with any full-sized bino with good eyecups, because they tend to fit against/into my facial anatomy well, and eyes are moist. It must depend on temperature and humidity, though I've never analyzed how, and may go away once the bino accommodates to the ambient temperature, when that's an issue.I am wondering why these are fogging so easily. I mean it’s winter here but I haven’t had them outside yet (I’m stuck inside with a cold that has been acting up poorly when I go outside). I find they do not fog if I hold my eyes slightly off the cups, but when placed comfortably on the cups they are fogging. The fogging is only on the outside of the glass though but still, what can I do to fix this or will I just have to live with it?