Children’s eyes running tears may be foreign body stimulation, excessive eye use and other factors, but also may be conjunctivitis, tear duct blockage and other reasons. 1. Children’s eyes into the eyelashes, gravel and other foreign objects to stimulate the eye surface caused by increased tear secretion; long-term use of electronic products lead to overuse of the eyes; these situations can lead to tears. 2. Bacteria, viruses and other pathogenic microorganisms cause acute inflammatory reaction of the conjunctiva after infection of the eye, increased capillary permeability, local edema and congestion, increased exudate, a large number of inflammatory substances stimulate tear secretion and tears. 3. Under normal circumstances, the tear fluid is synthesized by the lacrimal gland and other parts of the eye, and then flushes the cornea, sclera and other ocular surface tissues to the inner corner of the eye, and then sucked by the negative pressure of the lacrimal duct into the lacrimal duct until the nasal cavity. When the above structure congenital developmental abnormality, trauma, inflammation and other factors lead to blockage of the tear ducts, the tears can not enter the nasal cavity, so the eyes will flow tears. Children’s tearing eyes may be related to a variety of factors, after resting for a long time without relief, it is recommended to consult a doctor for a clear diagnosis.