I woke up this morning with this insane itch in my left eyeball. I have experienced this kind of itch before and have found out that in trying to "scratch" that itch, i.e., rub my eye lid in order to et some relief, I wind up with a blister on my eye. Like I said, it's an insane itch literally in the eyeball. What causes this? It doesn't happen often, but when it does, it can become a problem if I'm not careful with rubbing my eyelid to try to get some relief?