This has happened to me about 4-5 times over the last year or so, but at random it seems, one night I'll wake up in the middle of the night and not be able to open up my left eye because of this unbearable stinging sensation (it's always my left eye too). If I even try to pry it open a little bit the stinging gets worse. There's also some liquid substance that's dripping out of it too. I'm not sure if its just tears or not from the unbearable stinging. Every time though when I eventually am able to fall back asleep and wake up in the morning it is completely gone, and it doesn't return again for quite awhile. I was wondering if anyone knew of some possible explanations for this? One person I know already told me she gets that before she gets pink eye, but I've already had pink eye before when I was younger. I don't know, I can't figure it out.