However, when experienced without any other symptoms, they are rarely dangerous.
Electrical impulses in the brain can sometimes cause random spasms, which may result in a temporary eyelid twitch.
Sometimes, electrical activity in the brain causes nerve cells to flash signals to the muscles, which causes spasms. These spasms do not result from any internal or external stimuli, and they do not last long.
A one-time eyelid twitch is likely to be a result of this phenomenon.
If an eyelid twitch lasts for a few minutes to a few days, it could be caused by muscle overstimulation or fatigue due to:
Improving sleeping patterns, drinking less coffee, or using lubricating eye drops can usually resolve a simple eyelid twitch without medical attention.
If an eyelid twitch persists, a person should visit an eye doctor (ophthalmologist) as they may have a more serious condition that requires treatment.
The most common forms of chronic eyelid twitch are benign essential blepharospasm and hemifacial spasm.
Benign essential blepharospasm is a rare neurological disorder that causes spasms and muscle contractions around the eyes.
It may initially appear similar to a basic eyelid twitch, but it can deteriorate if left untreated. In some cases, the spasms become severe enough to squeeze the eyelids shut for hours at a time.
Researchers are still unsure as to the causes of essential blepharospasm. Most believe that it is a combination of both environmental and genetic factors.
A common theory is that these factors cause the brain's basal ganglia to malfunction. The basal ganglia are involved in regulating motor function, and they play a significant role in inhibiting erratic movements.
According to the National Organization for Rare Disorders, essential blepharospasm has several early symptoms that can help to distinguish it from a basic twitch:
- both eyes are involved
- the individual blinks frequently
- other muscles in the face experience spasms
- the eyes become irritated in bright light and stressful situations
- spasms usually last for an hour
Hemifacial spasm may initially be confused for a simple eye twitch as the condition usually begins by affecting the muscles surrounding the eye.
However, these spasms will eventually spread to other muscles on the same side of the face, causing the jaw, mouth, cheek, and neck muscles to contract spontaneously.
Hemifacial spasm is also a rare condition, but it is not caused by malfunction of any deep-brain structures. Instead, researchers believe that hemifacial spasm is caused by irritation of the facial nerve. This irritation could happen if a neighboring blood vessel puts too much pressure on the nerve.
Some other differences that might be useful in telling hemifacial spasm apart from blepharospasm and basic eye twitch are:
- the condition will usually affect one eye
- a person may experience facial muscle weakness between contractions
- hemifacial spasms tend to be consistent in intensity
- some people will hear a clicking sound in the ear on the affected side of the head
- hemifacial spasms can last anywhere from several days to a few months
An eyelid twitch may occur if the eyelid is inflamed.
Other motor disorders that share characteristics with benign blepharospasm and hemifacial spasm include:
- Bell's Palsy: This disorder causes temporary paralysis on one side of the face due to inflammation or trauma of the facial nerves. Most scientists believe it to be brought on by a viral infection.
- Meige Syndrome: This is a rare neurological disorder that involves simultaneous spasms in the cheeks, mouth, tongue, and neck.
- Tardive dyskinesia: This is a movement disorder characterized by involuntary writhing of the tongue, mouth, or lips, as well as increased blink rate. Most cases develop as a side effect of long-term antipsychotic medication use.
People with neurodegenerative diseases, such as multiple sclerosis or Parkinson's disease, may also experience eyelid spasms. However, a person affected by one of these disorders would also experience many other telling symptoms, such as cognitive difficulties, tremors, or difficulty moving around.
Tourette syndrome may also involve a more repetitive, patterned eyelid twitch that will likely be accompanied by at least one other motor or vocal tic.
In some cases, an eyelid twitch is caused by physical injury or irritation to the eye itself, rather than nerve irritation or neurological dysfunction. Some typical examples are:
- scratched cornea
- ingrown eyelash, or trichiasis
- inflamed eyelid, or blepharitis
- inward-folded eyelid, or entropion
Diagnosis and treatment
Both blepharospasm and hemifacial spasm require diagnosis and treatment from a specialist.
There are no specific lab tests to diagnose blepharospasm, so it is important to see an ophthalmologist.
An ophthalmologist will also perform a thorough clinical evaluation, taking into account the medical history of the person with an eye twitch.
If diagnosed with blepharospasm, there are several treatment options. These include:
- Botox (botulinum toxin) injection: This is considered to be the best form of treatment. Injections weaken the muscles that control the eyelid, helping to relieve any spasms. The effects of Botox usually last for about 3 months, so must be repeated.
- Oral medications: If Botox injections do not relieve symptoms, doctors may prescribe drugs that help to inhibit excessive motor signals from the brain.
- Surgery: This may be necessary if no other treatment is successful. According to the Benign Essential Blepharospasm Research Foundation, the most effective surgical remedy for blepharospasm is a myectomy. This procedure involves removing some or all of the muscles that are involved in eyelid closure. This option is a last resort and doctors will only do the surgery if blepharospasm is causing functional vision loss.
Another treatment under investigation is called deep brain stimulation.
In this method, an electrode is implanted into the brain to help regulate malfunctioning motor areas. Studies have shown that this can treat blepharospasm.
A Botox injection may help to treat eyelid twitching, particularly when caused by conditions such as blepharospasm or hemifacial spasm.
Hemifacial spasm cannot be diagnosed with a single test and requires a full specialist evaluation.
Treatments for hemifacial spasm are similar to those of blepharospasm. The two most common options are:
- Botox injections: This is the most common treatment method for hemifacial spasm.
- Surgery: The most effective surgery for hemifacial spasm is called microvascular decompression. In this procedure, a small sponge is implanted alongside the facial nerve to cushion it from the irritation-causing blood vessel.
Physical injuries or irritations to the eyelid or eye are usually not serious. Treatment could involve antibiotic ointment and steroids to decrease inflammation or minor surgery to correct eyelid folding.
Should you worry?
While it remains important to have an eyelid twitch evaluated if it lasts longer than a week, there is no reason for alarm. An eyelid twitch alone is rarely a sign of any serious neurological disorder, and it usually resolves by itself.
In the rare presentations of essential blepharospasm or hemifacial spasm, it is important to note that neither disorder is life-threatening and that both can be easily managed.