Eye twitching is causes blepharospasm. There are many causes of eye twitching. The common ones are alcohol, caffeine, fatigue, lack of sleep, physical exertion, smoking, stress, and irritation to the eye or eyelid. Chronic causes include inflamed eyelids, dry eyes, light sensitivity, and pink eye.
Deception involves acting in such a way which leads another person to believe something, that you, yourself, do not believe to be true (see Ekman; Miller & Stiff). The following example helps illustrate this point: Brad and Spencer. Brad and Spencer are both part of the same circle of friends.
In a practical sense military deception employs visual misdirection, misinformation (for example, via double agents) and psychology to make the enemy believe something that is untrue. The use of military camouflage, especially on a large scale, is a form of deception.