It is called FASICULATION and is due to involuntary bursts of muscle activity and is invariably innocent in nature.
When you read the above link by Buenchico and see the list of neurological disorders, do not panic, as fasiculation would only be one symptom among other more obvious symptoms in those neurological disorders.
pinky...that was just the point that i was making above, eye twitches, myoclonus, fasiculation whatever term one uses is almost always innocent, but webs site such as above do not emphasis this or even underline it to put the picture in some sort of perspective and can be innocently misleading and scarring.
Ho ho, just reminded me when I was a teen I had a friend who had a nervous eye twitch. Her mum would glare at her for ten minutes and then scream STOP THAT NOW! to help her out. It didn't work, can't think why.....