Hemifacial spasm usually affects one-half of the face. This differentiates it from blepharospasm, which usually involves twitches with both eyes at the same time. When hemifacial spasm affects ...

Hemifacial spasm (HFS) is a neurological disorder manifested by twitching ... They are generally not painful but may impact vision because of involuntary eye closure. In contrast to blepharospasm, a ...