Twitching and throbbing of the left eye may be caused by excessive fatigue, environmental factors, conjunctivitis and so on. 1. Overfatigue: If you look at products such as cell phones or computers for a long time, take a bad rest, or use your eyes excessively, it may lead to overfatigue of the eyes, causing spasms or pain in the left eye and accompanied by twitching symptoms. It can be relieved after resting. 2. Environmental factors: under the continuous stimulation of external light, such as being under strong or low light for a long time, it may also cause the patient’s eyes to throb. 3. Conjunctivitis: If the patient suffers from conjunctivitis, the inflammation can stimulate the eye surface tissues, leading to spasm of the patient’s eye muscles, thus causing the patient’s eyes to jump. If the left eye has been twitching and throbbing patients, should go to the regular hospital in time, under the guidance of professional doctors for treatment.