Tears and blurred vision in the left eye may be caused by overuse of eyes, infectious factors, dry eye disease, glaucoma and other factors. 1. Excessive eye use: Playing cell phone or watching computer for a long time, resulting in excessive eye fatigue, there will be tears in the left eye, or both eyes, accompanied by blurred vision, which can be improved after reasonable rest. 2. Infection: Conjunctivitis or keratitis, due to the presence of infection, there will often be tears and blurred symptoms, may also be accompanied by photophobia, eye swelling, redness, purulent discharge and other symptoms. 3. Dry eye: In the early stage of dry eye, blurring and tearing are common symptoms, which may be accompanied by burning sensation and redness of the eyes, which usually improve after blinking. 4. Glaucoma: It may be related to heredity, infection, trauma and other factors, and can cause blurred vision and tearing, which may be accompanied by headache, pain around the eyes, redness and other symptoms, and in severe cases, it may cause optic nerve atrophy. If the blurring of tears in the left eye lasts for a long time and is accompanied by other obvious abnormal symptoms, it is recommended to go to the ophthalmology department of the hospital for appropriate examination and treatment.