There's a common saying: "A twitching left eyelid means good fortune, a twitching right eyelid means bad luck." Actually, eyelid twitching has nothing to do with good or bad fortune, but it may be related to facial muscle spasms.

Hemifacial spasm, also known as facial tic, refers to paroxysmal, repetitive, involuntary twitching of the facial muscles innervated by the facial nerve. It typically manifests as eyelid twitching, twitching of the corner of the mouth, etc. There is no significant gender difference in patients. During an attack, the affected area is usually unilateral (one side of the face), with bilateral attacks accounting for only 0.5%. Hemifacial spasm begins in the lower eyelid and gradually expands, potentially affecting the corner of the mouth, other facial muscles, and the platysma muscle. There are usually no warning signs before an attack. During an attack, the muscles twitch rapidly and frequently, each episode lasting from a few seconds to a few minutes, with the patient appearing normal during the intervals between attacks. Attacks can be triggered by voluntary facial movements, chewing, or involuntary facial expressions, and can be aggravated by emotional excitement, tension, fatigue, or prolonged reading, and can be relieved by rest or emotional stability.

Some cases of hemifacial spasm are caused by diseases of the head and face, such as facial nerve injury or facial neuritis, which can lead to facial paralysis and hemifacial spasm during the recovery period. Cerebellopontine angle and skull base arachnoiditis affecting the facial nerve can also cause hemifacial spasm. Hemifacial spasm is treatable; for example, microvascular decompression of the facial nerve can control spasms in 90% of patients and stop them in half of them.

Eyelid twitching can be divided into two types: "physiological" and "pathological".

Experts explain that eyelid twitching, medically known as blepharospasm or blepharospasm, is a sudden, repetitive tremor or spasm caused by autonomic nervous system dysfunction and impact on the fibrous portion of the orbicularis oculi muscle in the eyelid. Eyelid twitching is divided into two types: "physiological" and "pathological," with the former accounting for the vast majority.

Physiological twitching: It is likely to occur when the eyes are overused or tired, when there is excessive mental tension, excessive stress, or excessive smoking and drinking. The duration of the attack is short (usually a few seconds) and the degree of twitching is not severe.

"Pathological" eyelid twitching can be caused by refractive errors (myopia, hyperopia, astigmatism, etc.), foreign bodies in the eye, trichiasis, conjunctivitis, keratitis, etc. It is characterized by frequent attacks, long duration, and large amplitude of twitching. Some people may also experience twitching of the eyebrows, forehead, corner of the mouth, or even half of the face. In particular, eyelid twitching caused by facial muscle spasms is 99% due to compression and stimulation of the facial nerve that controls eyelid muscle movement by abnormal blood vessels in the brain, and 1% due to intracranial tumors or arachnoid adhesions stimulating the facial nerve. Therefore, it is also considered a sign of intracranial diseases.

What causes eyelid twitching?

1. Excessive fatigue

Insomnia and lack of rest caused by staying up late, or excessive fatigue from overwork, can all cause eyelid twitching.

2. Nervousness

When the body experiences stress, such as before an exam, the brain doesn't get enough rest, which can cause eyelid twitching.

3. Disease

Eye diseases such as myopia, hyperopia, astigmatism, conjunctivitis, and keratitis can cause eyelid twitching. In rare cases, eyelid twitching may also be caused by intracranial tumors, cysts, or inflammatory adhesions compressing the facial nerve. In addition, some people experience intracranial nerve compression from tortuous blood vessels in their youth without experiencing any abnormal sensation. In middle and old age, due to increased blood pressure and arteriosclerosis, the strong pulsation of blood vessels can impact the nerve, causing eyelid twitching. Traditional Chinese medicine also believes that blood deficiency can cause eyelid twitching.

4. Improper use of eyes

Prolonged computer use can lead to dry eyes, eye strain, and frequent eyelid twitching.

5. External stimuli

Strong light, medications, and foreign objects can also cause eyelid twitching. In addition, smoking and drinking alcohol can irritate the eyes and lead to eyelid twitching.