Involuntary eyelid twitching is medically known as myokymia. In most cases, the spasm occurs in the lower eyelid of one eye, though it can sometimes affect the upper eyelid as well.
It usually starts suddenly and ends quickly. However, medical consultation is necessary if the twitching persists for several weeks or even months.
Common causes of eyelid twitching include:
Stress
Fatigue
Insomnia
Eye strain
Consumption of caffeine and alcohol
Dry eye syndrome
Deficiency of micronutrients such as magnesium and calcium
People suffering from myokymia are advised to get enough sleep and rest, reduce eye strain, and avoid stressful situations.