An<unk>  is a general term for involuntary spasms of the<unk>  muscles. In some instances, the<unk>  may repeatedly close (or nearly close) and re-open.
Eyelid twitch
Moro reflex
Optokinetic reflex
Ankle reflex
Baroreflex
Bezold-Jarisch reflex
Biceps reflex
Acoustic reflex