Red blood in the eyes of 4-month-old babies has different treatments according to different causes. Red blood in babies may be caused by allergic conjunctivitis, inverted eyelashes and many other reasons. It is necessary to consult a doctor in time to find out the cause and treat the symptoms. 1. Allergic conjunctivitis: baby immunity is low, if the eyes come into contact with some animal hair, pollen, etc., it is easy to induce allergic conjunctivitis, causing the symptoms of red bloodshot eyes. Try to avoid contact with suspected allergens, can be used locally 0.1% dexamethasone, 0.1% epinephrine and other drugs. 2. Inverted eyelashes: When eyelashes grow toward the eyeball, they can cause long-term irritation to the eye, resulting in the symptom of red bloodshot eyes. Inverted eyelashes can regenerate by simply removing them, and the irritation may be more pronounced with new growth. A small number of implanted eyelashes can be electrolyzed. Those with a majority of implanted eyelashes require surgical correction. All of the above medications should be used under the guidance of a doctor, avoid self-medication. 4-month-old babies with red blood in the eyes, it is recommended to go to the hospital in a timely manner, to find out the hospital for symptomatic treatment.