The orbicularis oculi, a muscle within the eyelids, is responsible for closing the eyes. The orbicularis oris muscle is innervated by the facial nerve, which, unlike the nerve that moves the eyes, emanates from the brain, passes through the inner ear, passes through the facial nerve canal, and then travels under the skin for some distance before innervating the orbicularis oris muscle. It can involve the upper or lower eyelid, and it can be assumed that the stimulated area should be near the throbbing muscle. This condition is often associated with exertion, lack of sleep, heavy drinking, excessive smoking, and ionic disturbances. This type of eyelid fluttering is very common and tends to stop as the influencing factors are removed, usually temporarily. In slightly more severe cases, the eyelid throbbing involves the entire orbicularis oculi muscle. Since the orbicularis oris muscle is responsible for closing the eyes, the patient will involuntarily force the eyes to close when the eyelid fluttering occurs. If both eyes are involved, the fluttering may cause temporary loss of vision. This can lead to accidents if you drive. If this condition persists for a long time without relief, treatment is needed. In the most severe cases, the eyelid fluttering is accompanied by muscle spasms on one half of the face, which manifests as eyelid twitching along with twitching of the face and corners of the mouth on the same side, a condition we medically call hemifacial spasm. This condition involves a wide range of muscles, indicating that the stimulated facial nerve trunk, and in fact confirms that this speculation is correct. It is now believed that the stimulated part of the facial muscle spasm is the trunk of the facial nerve after it emanates from the brain, and that the stimulating factor is usually vascular compression, or occasionally, tumor compression. Therefore, in any patient presenting with hemifacial spasm, an MRI scan or CT scan of the head is required to rule out the possibility of a tumor. For patients with facial muscle spasms, medication can be tried first, and if it is not effective, surgery can be considered to relieve the irritation of the facial nerve trunk by blood vessels and other factors.