Tears drain through a precise, narrow system
Tears are produced continuously by the lacrimal gland, which sits beneath the upper eyelid, and by accessory glands distributed across the conjunctiva. These tears spread across the eye surface with each blink, lubricating and protecting the cornea. The used tears are then drained away through a series of small channels that connect the eye to the inside of the nose.
The drainage begins at the puncta, two tiny openings visible as small dots at the inner corner of each eyelid. Tears enter through the puncta and pass through narrow channels called the canaliculi into the lacrimal sac, a small reservoir that sits in a bony groove beside the nose. From there, tears drain downward through the nasolacrimal duct into the inside of the nose. This is why crying makes the nose run.
A useful analogy: the tear drainage system works rather like the gutters and downpipes of a house. Tears are the rainwater, the puncta are the gutters, and the nasolacrimal duct is the downpipe. A blockage anywhere in this system causes overflow, tears running down the face rather than draining internally.
How tears drain through the lacrimal system
Gradual narrowing is the most common cause in adults
In adults, blockage most commonly develops gradually as the result of age-related scarring and narrowing of the duct. Chronic low-grade inflammation of the nasal mucosa, previous episodes of infection, trauma, or certain medications can all contribute.
The blockage is usually partial initially, the duct narrows rather than closes completely. Patients often notice that the eye waters more in cold or windy weather, or when reading, because tear production is briefly increased and the drainage system cannot keep pace. Over time, the blockage typically becomes more complete and the watering more constant.
In newborns, a blocked nasolacrimal duct is very common and usually resolves spontaneously in the first year of life. In adults, spontaneous resolution is less likely, and most persistent blockages require treatment.
Dacryocystitis
When the nasolacrimal duct is blocked, tears cannot drain and accumulate in the lacrimal sac. This stagnant fluid provides an environment for bacterial growth. The result is dacryocystitis, infection of the lacrimal sac.
Acute dacryocystitis presents as a painful, red, swollen lump at the inner corner of the eye. It is often accompanied by a discharge from the punctum when pressure is applied to the swelling. In some cases, a pointing abscess develops that requires surgical drainage.
- You develop a painful swelling or redness at the inner corner of the eye
- The swelling is tender to touch, spreading, or accompanied by fever
- You notice discharge coming from the inner corner
Acute dacryocystitis requires antibiotic treatment and sometimes surgical intervention. Chronic dacryocystitis is less dramatic but persistent: patients notice a watery or mildly sticky eye and a small soft lump at the inner corner that can be compressed to produce a small amount of mucoid discharge.
From syringing to surgery
Treatment depends on the degree and site of the blockage, and on how much the symptoms are affecting quality of life.
Syringing and probing
A simple outpatient procedure in which a blunt cannula is passed through the punctum and the drainage system is irrigated with saline. This confirms whether a blockage is complete or partial, and can sometimes temporarily relieve a partial obstruction. It is useful for diagnosis and for patients who are not suitable for surgery.
Dacryocystorhinostomy (DCR)
The definitive treatment for nasolacrimal duct obstruction. DCR creates a new drainage channel between the lacrimal sac and the nasal cavity, bypassing the blocked duct entirely. A small silicone stent is usually placed through the new opening and left in position for several months while healing occurs.
DCR can be performed through an external incision beside the nose or via the inside of the nose using an endoscope. Both approaches have success rates of around 90% or better. The operation is usually performed under local or general anaesthetic as a day case procedure.
Nasolacrimal duct obstruction treated with DCR surgery
Punctal and canalicular problems
If the blockage is at the level of the punctum rather than further down the drainage system, treatment options include punctal dilation, punctoplasty (surgically widening the punctum), or canaliculoplasty for canalicular stenosis.
Common questions
Can a blocked tear duct clear on its own?
In newborns, yes. The vast majority of neonatal nasolacrimal duct blockages resolve spontaneously within the first year of life. In adults, spontaneous resolution of a significant blockage is uncommon. Partial blockages may fluctuate, but a complete obstruction generally requires intervention.
Will I need surgery?
Not necessarily. Surgery (DCR) is the most reliable treatment for a complete blockage, but many patients with partial blockages manage well with observation or intermittent syringing. The decision depends on how much the symptoms affect daily life and whether there is any sign of infection.
What does a blocked tear duct feel like?
The main symptom is a persistently watery eye, often worse in cold or windy conditions or when reading. There may be a mild discharge or crusting, and occasionally a small lump at the inner corner of the eye. Pain is not usually a feature unless the sac becomes infected.
Is DCR surgery serious?
DCR is a well-established procedure with a high success rate. It is usually performed as a day case under local or general anaesthetic. Recovery involves some bruising and swelling around the eye for one to two weeks, but serious complications are uncommon.
Wondering whether your watery eye could be a drainage problem?
Use the Watery Eyes ToolLast medically reviewed: May 2026
This page is written for general educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. If you have concerns about your eye health, please consult a qualified healthcare professional. In an emergency, contact your nearest urgent eye care service or emergency department.
