The left eye always jumps, usually due to physiological factors, eye inflammation, facial neuritis and so on. 1. Physiological factors: generally due to frequent late nights, mental stress, excessive fatigue and other reasons for the orbicularis oculi muscle to appear temporary functional abnormalities. 2. Ocular inflammation: for example, blepharitis in the left eye, which may be caused by bacteria and other pathogenic microbial infections, and the inflammatory stimulus may cause eye muscle spasms, resulting in the performance of the left eye always jumping. 3. Facial neuritis: patients of any age may develop the disease, especially after a cold, due to viral infection of the facial nerve, making its function abnormal and caused. There are many reasons why your left eye keeps jumping, and you need to go to the ophthalmology department of the hospital as soon as possible to have a clear examination.