Eye tics or twitches -- medically known as myokymia -- are common, usually benign, involuntary movements of the eyelids. Although the lower lid most often twitches, both can be affected, according to Dr. Burt Dubow on the website All About Vision. Tics can be annoying, lasting for just a few minutes or for months. They are also difficult to diagnose and treat.
Eye Problems
Physical problems with the eye, such as dry eye, may precipitate eye tics. Dry eye occurs more frequently as people age and in those who spend a lot of time on the computer. Eyestrain from poor vision or an improper corrective prescription may also cause tics. Other causes may be irritation of the eye or eyelids from allergies or infections, such as conjunctivitis, and itching from inflammation of the lining of the eyeball and lower eyelid. Treating allergies with antihistamine drops may improve allergic symptoms and stop tics in some cases, but these medications may also worsen dry eyes, Dr. Dubow warns.
Stressors
Stress, fatigue and lack of sleep may cause eye tics in some people, according to MayoClinic.com.
Substances
Substances such as alcohol, caffeine and cigarettes may cause eye twitching. Medications such as anticonvulsants and antipsychotics may also cause eye tics, MayoClinic.com states.
Benign Essential Blepharospasm
Benign essential blepharospasm may start with eye twitching in response to stimuli such as bright lights, stress or fatigue. Over time, the spasms worsen; the eye may remain forcibly closed from blepharospasm for hours at a time, resulting in functional blindness, even though the eyes themselves are normal. Abnormalities within the basal ganglia, which are nerves found at the base of the brain that control movement, appear to cause benign essential blepharospasm. Drugs used to treat movement disorders, such as Parkinson's disease, may also cause the disease, according to the Benign Essential Blepharospasm Research Foundation. Botulinum toxin injected into the muscles may stop the spasms, reports Stephen Reich, M.D., of the Department of Neurology at the University of Maryland Medical Center.
Hemifacial Spasm
Hemifacial spasm, a disease seen more often in middle-aged and older women, occurs because of abnormalities in the seventh cranial nerve, the Merck Manuals Online Medical Library explains. In many cases, a loop of the artery compresses the nerve, causing symptoms that begin with eyelid twitching. Over time, the twitching spreads to the cheek and mouth and may occur almost continuously. Botulinum toxin injected into the affected muscles may relieve symptoms.
Other Brain and Nerve Disorders
Brain and nerve disorders may cause eyelid twitching. MayoClinic.com reports such conditions include Bell's palsy, Tourette's syndrome, dystonia, cervical dystonia and Parkinson's disease.
