There are many reasons that cause eye congestion without pain or itching, such as dry eye, conjunctival blood vessel rupture, and conjunctival compensatory congestion. 1. Dry eye: mainly caused by insufficient tear secretion or abnormal composition in tears, long-term dryness of eyes and dryness of eyeballs will lead to dilatation and congestion of blood vessels in the conjunctiva if not treated in time. 2. Conjunctival blood vessel rupture: mainly due to long-term eye fatigue or staying up late, vigorously rubbing the eyes, drinking alcohol, etc., leading to conjunctival blood vessel rupture, resulting in symptoms of eye congestion, and conjunctival blood vessel rupture is usually painless and itchy, and can be relieved by itself. 3. Conjunctival compensatory congestion: mainly due to excessive eye use or other stimuli, such as rubbing the eyes, resulting in conjunctival compensatory congestion, painless and itchy, which can be gradually relieved after enough rest. If the symptoms are not relieved, it is recommended to go to the hospital for symptomatic treatment.