Essential or spontaneous blepharospasm is a rare focal dystonia without any known cause and affects individuals between 45 and 65 years of age. Although idiopathic in nature, essential blepharospasm is commonly associated with stress, fatigue or an irritant. The symptoms could be benign and transient or might cause significant lifelong challenges to the individual and even cause functional blindness in those rare cases.
Blepharospasm: It refers eyelid muscles around the eye which close involuntarily. This could cause loss of vision, especially while reading, headaches, and eyebrow strain. The early symptoms of blepharospasm include increased blink rate (77%), eyelid spasms (66%), eye irritation (55%), midfacial or lower facial spasm (59%), brow spasm (24%), and eyelid tic (22%).
Ptosis: Ptosis is may also be called Blepharoptosis. It refers to an eyelid which is droopy. This could cause a loss of vision, especially while reading, headaches, and eyebrow strain.