Excerpt from Natural Baby and Chilcare

Conjunctivitis (pink eye) is a common complaint in babies and children and can be caused by bacteria, virus, allergy, foreign body, blocked tear duct, or trauma. The term implies an inflammation of the conjunctiva (the mucous membrane that lines the inner surface of the eyelids and eyeball), when inflamed it appears 'pink.' The bacterial and viral infections are highly contagious. Signs and symptoms include red bloodshot eyes, tearing, swelling and inflammation of the eyelids, yellow-green discharge and sensitivity to light.

Blocked Tear Ducts
Plugged tear ducts occur in 6 percent of all babies and can be a problem up to one year of age. It can affect one or both eyes. By three to four weeks of age a newborns' eyes begin to tear. Normally, tears drain from the tiny tear ducts located at the inside corners of the eyes into the nose. A thin membrane covers the duct, and usually opens after birth. The blockage occurs when the membrane fails to fully open, and tears become backed up. The condition can recur, though usually by six month of age the duct stays open. In standard medical practice, persistent conditions are treated with a minor office procedure using a wire probe, however, some may require surgery. Common symptoms of blocked tear ducts range from persistent tearing and can lead to infection with redness and discharge.