Tear secretion is a normal protective function of the eye. Generally, occasional tearing due to emotional excitement or wind and sand irritation is a normal physiological reaction. And if there is frequent tearing, sometimes without any clear cause, pathological factors should be considered. Such as inflammation of the eye, irritation caused by the entry of foreign bodies in the eye, etc. The causes vary among patients of different ages. Newborns with frequent eye tearing should consider causes such as conjunctivitis, dacryocystitis or simple obstruction of the nasolacrimal duct and inverted eyelashes. A less common condition is a congenital condition, nasolacrimal duct fistula in newborns. Frequent tearing of the eyes in the elderly is commonly caused by chronic dacryocystitis, obstruction or narrowing of the nasolacrimal duct, bacterial or viral keratitis, and irritative tearing caused by irritation of the eye by the surrounding environment. Another common cause in elderly patients is laxity and aging of the eyelid skin, resulting in reduced tear drainage and unprovoked frequent tearing. In adolescents, the most common cause is visual fatigue due to overuse of the eyes, but it can also be due to various eye diseases such as pink eye, blepharitis, and lid gland dysfunction. In addition, in addition to the eye itself, there can also be diseases in other areas, such as allergic rhinitis and laryngitis, which can also cause tearing symptoms.