Frequent tearing of the eyes in infants is usually caused by obstruction of the tear ducts and inverted eyelashes.
If an infant has tear duct obstruction, it is usually caused by congenital developmental abnormalities, such as the lower end of the tear duct valve did not degenerate at birth, because of poor drainage of tears, the child may appear tearing.
Inverted eyelashes are also associated with congenital developmental anomalies. Usually, the lower eyelid is more likely to have inverted eyelashes than the upper eyelid, and the friction with the eyelashes damages the cornea, resulting in tearing, stinging and other uncomfortable symptoms in the child.
It is recommended that infants with frequent tearing and other discomforts be seen promptly for evaluation and treatment.