The left eyelid jumps for several reasons: First, excessive eye use, resulting in excessive neuromuscular tension fatigue, resulting in twitching of the eyelid muscles. Second, eye diseases, such as keratitis, because the inflammation stimulates the nerves, which leads to the constant twitching of the innervated muscles. Third, the nerves of the eye muscles are damaged or even the nucleus is damaged, such as neuropathy, disease in the brain where the nucleus is located, resulting in abnormal innervation function and thus muscle twitching, which is rare. Fourth, facial muscle spasm, although facial muscle spasm is manifested as twitching of one side of the face, but at first it will be manifested as muscle twitching around the eyes before facial muscle twitching occurs, so eyelid twitching may also be a pre manifestation of facial muscle spasm, which can be relieved by rest, avoiding cold, taking nerve-nourishing drugs, such as methylcobalamin, and treating primary brain diseases.