The upper eyelid of the left eye keeps jumping, which is a relatively common phenomenon in life and is clinically known as blepharospasm. This condition is due to the repeated contraction of the orbicularis muscle within the eyelid due to stimulation, which in turn manifests itself as the phenomenon of the upper eyelid of the left eye jumping all the time. The reasons why the upper eyelid of the left eye keeps jumping may be the following: 1. Physiological eyelid jumping: it may be due to mental tension, lack of sleep, excessive eye fatigue or excessive smoking and drinking, which causes excessive contraction of the orbicularis oculi muscle fibers, causing contraction and diastolic dysregulation, and the upper eyelid of the left eye keeps jumping; 2. Pathological eyelid jumping: it is commonly caused by facial muscle spasm, and may also be due to certain diseases, such as conjunctivitis and keratitis, as well as intracranial diseases, such as tumors, arachnoid adhesions, etc. In addition, stimulation of the eye by bright light or drops of medication to narrow the pupil may also cause the upper eyelid of the left eye to keep throbbing. It is recommended that patients pay attention to rest, ensure sufficient sleep, do not look at a certain object for a long time, relax their eyes properly, and can apply local heat and massage to help improve the symptoms of the left eyelid jumping all the time. If the patient has more serious eyelid jumping or other symptoms, such as pain, loss of vision, or twitching at the corners of the mouth, it is recommended that the patient go to the hospital for examination in time to clarify the cause and treat accordingly.