Caused by obstruction or narrowing of the nasolacrimal duct, this is a relatively common eye disease that occurs in middle-aged and elderly women, and is more common in rural and remote areas. It is commonly caused by trachoma, lacrimal trauma, rhinitis, nasal septum deviation, nasal polyp, inferior turbinate hypertrophy and other obstruction of the nasolacrimal duct, which prevents the discharge of tears and retains them in the tear sac for a long time. Tear overflow, mucus or purulent secretions from the tear dots and other symptoms. Clinical manifestations 1. Overflow of tears, conjunctival congestion in the inner canthus, and eczema on the skin. 2. Squeeze the lacrimal sac with a finger, and mucus or purulent secretions flow out from the tear dots. 3. Due to the large accumulation of secretions, the lacrimal sac gradually dilates and becomes cystic bulge below the medial canthal ligament. Tear overflow is a common and frequent disease in ophthalmology, mainly caused by nasolacrimal duct obstruction. “Artificial nasolacrimal duct stenting” is an emerging treatment for dacryocystitis through the implantation of artificial nasolacrimal ducts by interventional techniques, which is a minimally invasive treatment method. This technique is suitable for the treatment of chronic dacryocystitis, nasolacrimal duct obstruction, nasolacrimal duct stenosis, nasal lacrimal sac anastomosis reobstruction and other conditions. The technique involves retrograde dilatation of the nasolacrimal ducts from the nasal cavity, without incision and painless during the operation. No hospitalization is required and it does not affect daily life and work. Since the nasolacrimal duct stent is made of new artificial heart valve material, there is no rejection, no need to remove it after surgery, and it can be left in place for life, thus ensuring the efficacy. It has the following advantages: 1.Simple, safe and time-saving operation, no need for hospitalization; 2.Less bleeding and pain, which can be tolerated by patients; 3.No change in the original anatomical position, after the artificial nasolacrimal duct is blocked, it can be re-intervened or changed to other methods; 4.No skin incision, no scar on the skin surface; 5.Wide indications for the operation, and positive curative effect.