Red eyes without pain and itchiness may be caused by chronic conjunctivitis, dry eye, fatigue, foreign body in the eye, subconjunctival hemorrhage, drinking alcohol and other reasons. 1. Chronic conjunctivitis: Conjunctivitis is an inflammatory reaction of the conjunctival tissue that occurs under the action of external and body’s own factors, which may lead to red eyes. 2. Dry eye: Insufficient tear secretion or poor quality of tears may cause dry eyes as well as eye damage, leading to the occurrence of dry eye, so the phenomenon of red eyes will occur. 3. Excessive fatigue: the patient stays up late for a long time and uses his eyes too much, which leads to visual fatigue, and red eyes will appear. 4. Foreign bodies in the eyes: red eyes may occur when patients rub their eyes with their hands after foreign bodies such as flying mosquitoes, animal hairs, willow flakes, sand and dust particles enter their eyes. 5. Subconjunctival hemorrhage: generally seen in the elderly, rubbing the eyes hard, coughing violently, etc. can lead to subconjunctival hemorrhage, which can be manifested as red eyes. 6. Alcohol consumption: patients who drink alcohol will have red eyes and red head and face, and the symptoms can be relieved after the alcohol is metabolized. Red eyes are not painful and itchy symptoms, if not relieved after rest, should go to the regular hospital in time, clear cause, under the guidance of the doctor’s treatment. Usually pay attention to eye hygiene, pay attention to rest, avoid eating stimulating food.