The common causes of red blood in the eyes are bacterial conjunctivitis, eye fatigue, glaucoma, etc. You can follow the doctor’s instructions for the original cause of the disease to take treatment to eliminate. 1. Bacterial conjunctivitis: Bacterial conjunctivitis is mainly caused by bacterial infections, which need to be treated with antibiotic tears, such as levofloxacin eye drops, ofloxacin eye drops and so on. 2. Eye fatigue: If patients stay up late for a long time, long time looking at the cell phone, it will lead to overuse of the eyes, resulting in eye fatigue and redness, you need to pay more attention to rest, relieve eye fatigue, usually redness will disappear on its own. 3. Glaucoma: If glaucoma acute attack, it will cause intraocular pressure to rise, thus causing the phenomenon of conjunctival mixed congestion, the need to use eye drops to lower intraocular pressure to control intraocular pressure, such as hairy fruit rutaecarpine eye drops, latanoprost eye drops. All of the above medications must be used under the direction of a physician. There are many reasons why there is red blood in the eyes, should go to the hospital to clarify the cause of the disease, after diagnosis and then for the original cause of the treatment, not to private treatment, in order to avoid adverse situations.