eye twitching can have a variety of causes such as fatigue, too much caffeine, squinting alot or working in an environment where lighting is poor and you cannot see well. it can also be caused by staring at a computer screen for long periods of time.
treatments that may help include rinsing your eyes with warm water, using eye drops, applying hot or cold compresses and taking a hot bath.
not to scare you, but more persistent eye twitching can be a sign of stress, epilepsy or neurological damage.
if this concerns you, i would see an eye doctor or opthalmologist.