Are you taking mestinon? That will cause muscle twitches and I do get those on and off. When my dose got too high, I got them all over my body (trunk, neck, shoulders, eyes, arms, legs) and frequent urination and diarrhea so we knew it was too much. But even at the right dose, when I have a cup of coffee which enhances the effect, my eyelids will twitch for a little while .. .