Any kind of fatigue can also cause muscle spasms, which may include eye twitching. If you have been overdoing it at the gym, if you have been doing a lot of walking, or if you have been working late then your eyes might be tired and this muscle weakness can be seen in the form of twitching.
Of course the solution here is to listen to your body and to relax. Take a warm bath or try to relax your muscles through your diet: eating foods high in magnesium will often help as magnesium helps to relax the muscles and calm the mind.
