Not if one's healthy. Twitching of an eyelid, which happens in normal people, is called myokymia (an involuntary, spontaneous, quivering of a few muscle cell bundles within a muscle). Myokymia starts and stops spontaneously. In the eyelids, it can last a few minutes to a few days. One should see an ophthalmologist (md eye doctor) if such symptoms persist, keep recurring, or are combined with any other symptoms.
No . Usually most people experience twitches from time to time when they are tired, have eye strain( like too much computer), stress, lack of sleep, are bothered by the lights, have eye irritation. But if it keeps up for a while and does not stop while asleep or concentrating hard then you should see your doctor because it could be a sign of something else and your doctor can help you sort it out.