Constant pain in the right eye may be caused by physiological factors such as incorrect eye use and improper wearing of contact lenses, as well as other causes such as dry eye, conjunctivitis, glaucoma, and eye trauma. 1. Physiological factors: If you look at the cell phone or play with the computer for a long time may cause pain in the right eye, in addition, wearing poor quality contact lenses or contact lenses worn for too long, may also cause pain in the right eye. 2. Dry eye: Dry eye may be caused by excessive evaporation of tears, abnormal tear composition, and insufficient tear secretion. Patients will show eye fatigue, foreign body sensation in the eyes, dry eyes, eye pain, photophobia, etc. If patients have dry eye in the right eye, they will have the symptom of pain in the right eye all the time. 3. Conjunctivitis: Conjunctivitis may be caused by bacterial infection, viral infection, eye tumor, allergy, physical or chemical stimulation and other factors. Patients will have red eyes, dry eyes, eye pain, foreign body sensation and other manifestations, so patients with conjunctivitis in the right eye, will be manifested as right eye pain all the time. 4. Glaucoma: Glaucoma is considered to be caused by the obstruction of aqueous humor outflow, abnormalities in the anatomical structure of the eyeball, ocular trauma, and irrational use of medication. Patients will have headache, eye swelling, headache, nausea, blurred vision and other manifestations, thus patients will have the symptom of right eye pain all the time. 5. Other: patients with right eye pain is also considered to be eye trauma, eye foreign body, keratitis and other factors. For the exclusion of physiological factors caused by the right eye pain, the patient needs to consult a doctor in time, the doctor will choose the appropriate measures for the cause of treatment.