Conjunctivitis in 3-month-old babies is most commonly caused by bacterial infections or allergic conjunctivitis, which can be difficult to heal on its own. It usually needs to be treated with medication before it can gradually get better. Bacterial conjunctivitis is caused by improper eye hygiene and bacterial infection, which is mainly manifested by yellow pus-like eye droppings, especially in the early morning, and even during the day there will be a large amount of eye droppings, and need to use antibacterial drugs to be able to control, such as Tobramycin eye drops for anti-inflammatory treatment. Allergic conjunctivitis is mainly caused by allergens and conjunctival allergy and a reaction, mainly to the white of the eye congestion, and the child’s rubbing and blinking phenomenon will increase, is a kind of itchy eyes, usually need to use anti-allergy drops, such as orotidine eye drops can relieve the symptoms.