Involuntary Eye Twitch

You know when your eyelid subtly twitches like a little heartbeat? That's been happening to my right eye for about two weeks now. It started in Florida. I thought it was being triggered allergies (they were bad when I was there), but now since I'm home I'm not so sure. It could be caused by stress, but I'm not really stressed out right now (unless I'm seriously surpressing it.)

It's so irritating.