The constant jumping of the upper eyelid of the left eye may be related to certain diseases, or it may be caused by non-disease factors such as medications, environmental factors and lifestyle. 1. Disease factors: Refractive error or wearing inappropriate glasses can lead to eyelid jumping. Inflammatory diseases of the eye, such as conjunctivitis, keratitis, etc., can lead to involuntary contraction of local muscles, causing eyelid jumping. Facial muscle spasms on the left side can cause left eyelid jumping. Intracranial lesions, such as tumors, inflammation and other diseases, can also cause eyelid jumping. 2. Non-disease factors: the use of eye drops or ointment, etc., may irritate the eyes, causing eyelid jumping. Prolonged exposure to bright light or low light environment can also cause eyelid jumping. Excessive eye use, visual fatigue, long-term tension and depression, often eat spicy food can also cause eyelid jumping. If the upper eyelid of your left eye keeps jumping, we suggest you go to the hospital to find out the cause and get timely treatment.