Many parents of children complained of tearing symptoms at birth or soon after birth, single or double eye onset, some have yellow mucopurulent discharge, mostly diagnosed as “lacrimal duct obstruction combined with dacryocystitis” To understand the cause of this disease, we must first look at the developmental process of the lacrimal duct: fetal development, the lacrimal duct in the embryo after the 6th week During fetal development, the lacrimal duct gradually begins to form a duct, the upper and lower tear dots open in the 7th month, and the lower nasolacrimal duct opens in the 8th month. The Hasner valve at the lower end of the nasolacrimal duct is like a door, and its role is particularly important. Congenital lacrimal stenosis or obstruction is caused by the non-opening of the Haner’s membrane valve. Tears and secretions cannot be drained through the lacrimal duct and accumulate, and when combined with viral or bacterial infections, they form a dacryocystitis and a large amount of purulent discharge. In terms of treatment, because most congenital Hasner’s valve obstruction can open up on its own 4-6 weeks after birth, children within 2 months of birth can be treated conservatively with antibiotic eye drops and massage, which is done by gently rubbing with the fingertips for about 5-10 minutes below the inner corner of the affected eye, next to the nasal bulge (which is generally the location of the tear sac). It is recommended to massage before dropping the drops, eye drops 4 times a day. If conservative treatment is not effective, the child can wait for 3.5 months before going to the hospital for lacrimal duct irrigation. The function of lacrimal duct irrigation is to: 1) flush out purulent secretions from the lacrimal sac and tear ducts to reduce the symptoms of infection; 2) flush out the obstructed valves to clear the tear ducts. In some cases, if the valve is thick or has been combined with a more obvious infection, or if the tear duct wall has been damaged and the adhesions are repaired, and if the lacrimal duct is still not open after several lacrimal flushes, the lacrimal duct canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal canal.