Many people become particularly “weepy” when they reach middle age, and their eyes tend to tear up, even when they gently squeeze the corners of their eyes with their hands, and yellowish-white pus flows out from the tear dots. This is not that they become sentimental, but chronic lacrimation is at work. Chronic dacryocystitis is an eye disease caused by blockage or narrowing of the nasolacrimal duct. When the nasolacrimal duct is blocked, the tears cannot be discharged and are “blocked” inside the tear sac for a long time. There are some bacteria in the tear fluid, such as pneumococcus, staphylococcus, etc., they quietly breed in the tear sac, constantly stimulating the tear sac wall, it will cause chronic inflammation of the tear sac mucosa, thus producing mucus or purulent discharge. You should not underestimate the “teary” eyes, but it has many potential hazards. You should know that the pus that fills the tear sac contains a lot of bacteria, which acts as a reservoir of bacteria that can drain out with the pus and infect the eye at any time. If the black eye is injured, the bacteria hidden in the pus will take advantage of the situation and cause keratitis or corneal ulcers, which can affect vision in the lighter cases by leaving a scar on the cornea after healing, or blindness due to corneal perforation in the more serious cases. Because chronic dacryocystitis is a threat to the eye, ophthalmologists often compare chronic dacryocystitis to a “time bomb” next to the eye. Chronic dacryocystitis can also adversely affect eye surgery and can cause serious post-surgical infections. For example, cataract patients with chronic dacryocystitis must wait until the chronic dacryocystitis is completely cured before undergoing cataract surgery. Medication is generally effective for chronic dacryocystitis, which is often prolonged, and surgery is still the main treatment. The traditional lacrimal sac nasal anastomosis is performed by an ophthalmologist via an external nasal route, which will inevitably leave skin scars on the nasal side and affect the aesthetics. With the application of nasal endoscopy technology, ENT doctors use the minimally invasive features of nasal endoscopy technology to perform lacrimal sac nasal anastomosis via nasal endoscopy, which has a short operation time, little pain, high cure rate and no facial surgical incision, leaving a beautiful look for patients.