Well, it sounds as if you are not in a relaxed state in which to sleep (WILD) at that moment.

If you were to fall asleep, you would be doing so with your eyes closed, unless the room is pitch black. So, being that they are opening, I guess it makes sense to make the assumption that you are not fully tired/relaxed to correctly enter the WILD.

Earlier today I began my attempt with the same problem as you...eyes were jittery and really making it hard to do anything more. After slowing my breath, and fully relaxing, my eyes easily shut. Just control yourself, or require more sleep.