I get this from time to time in my eyes and sometimes in my shoulder/arm muscles.
The only correlation I've noticed is tiredness. I used to think it was a combination of tiredness and caffeine ODthat goes with it, but more recently have stopped drinking caffeine and still get the occasionaly twitches.
Remedy = 1 week of early nights, lots of salad, fruit and veg, lay off the caffeine and alcohol.
Feel right as rain after that. Then again, that's just me. Are you tired/stressed at the moment?