Blepharospasm

n. constant involuntary winking (Medicine)

A blepharospasm ('eye twitching') is any abnormal tic or twitch of the eyelid (from blepharo, eyelid, and spasm, an uncontrolled muscle contraction) . However, it is normally distinguished from less serious disorders and refers to Benign Essential Blepharospasm, a focal dystonia (a neurological movement disorder involving involuntary and sustained muscle contractions) of the muscles around the eyes. The cause is often undetermined, but fatigue or an irritant are possible contributing factors. Symptoms usually last for a few days then disappear without treatment, but in some cases the twitching is chronic and persistent. Occasionally, the symptoms are severe enough to result in effective blindness.
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Bleph·a·ro·spasm n. Spasmodic winking caused by the involuntary contraction of an eyelid muscle. blepharospasm spasm of the orbicularis oculi muscle [more]Blepharospasm - Community and Resources

Noun
1. spasm of the eyelid muscle resulting in closure of the eye
(hypernym) spasm, cramp, muscle spasm

The involuntary, forcible closure of the eyelids. The first symptoms may be uncontrollable blinking. Only one eye may be affected initially, but eventually both eyes are usually involved. The spasms may leave the eyelids completely closed causing functional blindness even though the eyes and vision are normal. Blepharospasm is a form of focal dystonia.