Why Is My Eye Leaking? Causes and What to Do

A leaking eye almost always comes down to one of two problems: your eye is making too many tears, or the tears you’re making aren’t draining properly. The most common cause in adults is a blockage somewhere in the tiny drainage system that normally channels tears from the eye surface into the nose. But the list of triggers runs surprisingly long, from dry eye (yes, dry eyes can make your eyes water) to eyelid looseness, allergies, infections, and even neurological conditions that rewire tear production.

How Tears Are Supposed to Drain

Every time you blink, a small muscle behind the inner corner of your eye contracts and squeezes tear fluid through two tiny openings called puncta, one on each eyelid near the nose. From there, tears travel through narrow channels called canaliculi and into the lacrimal sac, a small pouch that sits in a bony groove along the side of the nose. The sac empties into the nasolacrimal duct, which carries tears down into your nasal cavity. That’s why your nose runs when you cry. The whole system works like a pump: the muscle contraction during blinking compresses different segments of the drainage channels in sequence, pushing fluid toward the sac and then down into the nose.¹

When any part of this system gets blocked, narrowed, or misaligned, tears have nowhere to go except over your eyelid and down your cheek. Doctors call this overflow tearing, or epiphora, and it accounts for the majority of “leaking eye” complaints.

Blocked Tear Ducts Are the Most Common Culprit in Adults

In a study of adults referred to an eye surgery clinic for chronic tearing, acquired nasolacrimal duct obstruction accounted for about 58% of cases, making it the single most frequent diagnosis. The next most common was punctal stenosis, where the tiny drain openings on the eyelid narrow or close, which made up roughly 16% of cases.²

Why do these blockages happen? In most cases, a slow inflammatory process gradually narrows the duct. Immune cells and scar-forming proteins build up inside the channel wall over time, shrinking the opening until tears can no longer pass through. Women appear to be more vulnerable, possibly because their nasolacrimal ducts tend to be anatomically narrower to begin with. Other structural factors that can contribute include a deviated nasal septum and enlarged turbinates (the bony ridges inside the nose that warm and filter air).³

Less commonly, a blockage develops secondary to something more specific. Among patients who needed surgery for secondary nasolacrimal duct obstruction, the documented causes included sinonasal cancer, chronic inflammatory disease, trauma, and prior head and neck radiation.⁴ These secondary causes are far rarer than the garden-variety blockages that accumulate with age, but they’re worth knowing about if tearing comes on suddenly or is paired with other symptoms like facial pain or a visible mass near the eye.

The Dry Eye Paradox

One of the most counterintuitive causes of a watery eye is dry eye itself. When the surface of the eye isn’t adequately lubricated, either because you aren’t producing enough baseline tears or because the tear film is unstable and evaporates too quickly, the exposed cornea sends an irritation signal. Your lacrimal gland responds by dumping a flood of watery “reflex” tears, which are chemically different from the steady-state tears that normally keep your eyes moist. These reflex tears don’t have the right oil-and-mucus composition to stick around and lubricate. They just roll off, leaving you paradoxically both dry and teary at the same time.

This reflex tearing mechanism has been observed in other eye-surface conditions too. Research on pterygium, a fleshy growth on the white of the eye, found that early-stage growths were associated with corneal drying and increased reflex tear production.⁵ The pattern is the same: irritation on the eye surface triggers a reflexive tear surge that doesn’t address the underlying problem. If your eyes feel gritty or tired yet also water frequently, especially in wind, air conditioning, or while staring at a screen, dry eye with reflex tearing is high on the list of explanations.

Eyelid Problems That Redirect Your Tears

Your eyelids do more than blink. They also position the punctal openings so that each blink catches tears and feeds them into the drainage channels. When the lower eyelid loosens or turns outward, a condition called ectropion, the punctum can flip away from the eye surface. That small shift is enough to break the drainage pump entirely. In a study that specifically examined punctal function during blinking, patients with medial punctal ectropion showed a failure of the punctum to rotate inward during blinks, and every one of those patients suffered from tearing in the affected eye.⁶

Ectropion becomes more common with age as the tendons and tissues supporting the lower eyelid gradually stretch. It can also develop after facial surgery, scarring, or skin conditions that tighten the skin below the eye. Mild cases sometimes respond to minimally invasive treatments. One technique uses a specialized laser applied to the inner surface of the lower lid to tighten the tissue and reposition the punctum.⁷ More advanced cases often need surgical tightening of the eyelid.

The opposite problem, entropion, happens when the eyelid turns inward so that eyelashes rub against the eyeball. This causes irritation and reflex tearing rather than a drainage failure. Either direction of eyelid malposition can leave you with a persistently watery eye.

Allergies and Infections

Allergic conjunctivitis is one of the most common reasons for eyes that water seasonally or in response to specific triggers like pet dander or dust. When allergens land on the eye surface, immune cells in the conjunctiva release histamine and other inflammatory chemicals, causing itching, redness, swelling, and a flood of watery tears. The tearing is usually accompanied by intense itchiness, which helps distinguish allergies from a duct blockage (duct blockages don’t typically itch at all).

Bacterial and viral infections of the eye surface produce a different kind of discharge. Bacterial conjunctivitis, commonly called pink eye, tends to produce thick, yellow-green discharge that can glue your eyelids shut overnight. Viral conjunctivitis more often causes a thinner, watery discharge alongside redness, though it can still be sticky. Viral infections are extremely contagious and usually run their course in one to two weeks. Bacterial infections may need antibiotic eye drops, especially if the discharge is heavy.

A stye or chalazion, both of which involve blocked or infected oil glands in the eyelid, can also cause localized tearing. These usually appear as a painful or painless lump on the lid margin and resolve on their own or with warm compresses. Persistent lumps that don’t go away deserve evaluation, since rarely they can mimic more serious conditions.

Neurological Causes and “Crocodile Tears”

Sometimes a leaking eye traces back not to the eye itself but to the nerves that control tear production. The most well-known example is gustatory hyperlacrimation, colloquially called “crocodile tears,” where your eye waters while you eat. This happens after damage to the facial nerve (cranial nerve VII), typically from Bell’s palsy or surgery. As the nerve regenerates, some fibers that were originally headed for the salivary glands accidentally grow toward the lacrimal gland instead. The brain sends a signal to produce saliva, and the rewired nerve triggers tears at the same time.⁸

For people who find this disruptive, injections of botulinum toxin into or around the lacrimal gland can reduce the unwanted tearing while preserving enough baseline tear production to keep the eye lubricated.⁹

Facial nerve palsy can also cause tearing through a completely different mechanism. When the nerve isn’t working properly, the eyelid doesn’t close fully, leading to exposure and irritation of the cornea. But even after standard surgical correction for that, some patients still have persistent tearing. Research has identified an additional contributor: inversion of the meibomian glands (the oil-producing glands along the eyelid margin). In facial nerve palsy patients, these glands can flip inward, disrupting the oily layer of the tear film and triggering overflow tearing even when the drainage system itself is intact.¹⁰

Watery Eyes in Babies

If you’ve noticed a newborn or young infant with a constantly teary or goopy eye, there’s a good chance the nasolacrimal duct hasn’t fully opened yet. Congenital nasolacrimal duct obstruction is common, affecting somewhere between 5% and 20% of infants. The blockage is usually a thin membrane at the lower end of the duct that failed to open before or shortly after birth. Affected babies present with excessive tearing or mucoid discharge, and the skin around the eyelids can become irritated from constant moisture. Local infections like conjunctivitis sometimes develop and may need antibiotics.¹¹

The reassuring news is that most of these blockages resolve on their own as the baby grows. Conservative management includes gentle massage of the lacrimal sac (your pediatrician can show you how) and antibiotic drops if an infection develops. If the blockage hasn’t cleared by about twelve months, a doctor can perform a probing procedure to open the membrane. Probing works well for membranous blockages but is less effective when the obstruction involves bone or significant swelling from infection.¹¹

A Rare Cause Worth Knowing About

Very rarely, what looks like a tearing eye turns out to be something else entirely. In at least one documented case, a patient presented with what appeared to be epiphora after orbital surgery, but analysis of the fluid revealed it was cerebrospinal fluid (CSF) rather than tears. The leak was traced to a defect in the orbital roof created during the prior surgery. Glucose and chloride levels in the fluid confirmed the diagnosis, and placing a lumbar drain significantly reduced the fluid coming from the eye.¹²

A CSF leak is not something to diagnose yourself, and it’s an extremely uncommon cause of a watery eye. But it’s clinically important because the fluid is clear and watery, easily mistaken for ordinary tears. The distinguishing feature is usually context: CSF leaks tend to follow head trauma, skull base surgery, or severe sinus disease. If you’ve had any of those and develop unilateral tearing that seems excessive or doesn’t respond to typical treatment, mention that history to your doctor.

What Treatment Looks Like for Blocked Ducts

When a blocked nasolacrimal duct is confirmed as the cause, the standard surgical fix is dacryocystorhinostomy, or DCR. The procedure creates a new passage between the lacrimal sac and the nasal cavity, bypassing the blocked duct entirely. It can be done from outside (through a small skin incision near the nose) or from inside (endoscopically, through the nostril). Both approaches have strong track records.

In one large follow-up study, patients who underwent endoscopic DCR showed significant improvement in both subjective symptoms and measurable tear buildup (assessed by the height of the tear film meniscus). At twelve months, the vast majority maintained their improvement, though a small number experienced recurrence.¹³ Another study found that beyond simply stopping the tearing, DCR also improved the overall health of the eye surface. Before surgery, patients had worse tear film stability and more corneal surface damage compared to healthy controls. After surgery, those measurements returned to normal levels.¹⁴

Quality of life tends to improve meaningfully too. Patients who had external DCR showed decreases in tear meniscus height, depth, and area after surgery, along with significant improvements in both symptom scores and general well-being scores.¹⁵ For people who’ve been dealing with constant tearing for months or years, the relief after successful surgery can be dramatic.

When to See a Doctor

Occasional tearing from wind, cold air, yawning, or bright light is completely normal. Reflex tearing from brief irritants is your eye doing exactly what it’s supposed to do. But certain patterns warrant professional evaluation:

Persistent one-sided tearing: A constantly watery eye on just one side is more likely to indicate a drainage blockage or eyelid problem than a systemic cause like allergies, which typically affects both eyes.
Discharge that is thick, colored, or sticky: This points toward infection rather than simple overflow tearing and may need antibiotic treatment.
Painful swelling near the inner corner of the eye: This can signal dacryocystitis, an infection of the lacrimal sac that develops when a blocked duct traps bacteria. It sometimes needs antibiotics or even urgent drainage.
Tearing after facial surgery or head injury: As noted, this combination raises the possibility of a CSF leak or structural damage to the drainage system.
A baby whose tearing or discharge worsens rather than improves: While congenital duct blockages usually resolve, worsening symptoms or recurrent infections suggest the blockage may not clear on its own.

An eye doctor can distinguish between overproduction and drainage failure using a few straightforward tests. Fluorescein dye placed in the eye should drain into the nose within a few minutes if the system is open. If the dye sits on the eye surface without draining, a blockage is likely. Irrigation of the drainage channels with saline can further localize where the obstruction sits. Imaging like a CT scan of the drainage pathways is sometimes needed for surgical planning.

Emotional Tears Are a Different Story

If your eye is “leaking” because you’re upset, moved, or overwhelmed, that’s a completely different biological process from the drainage and irritation problems described above. Emotional tearing appears to be unique to humans among all species.¹⁶ Other animals produce tears to protect and lubricate their eyes, but producing visible tears in response to emotional experiences is something only we do.¹⁷

Emotional tears are triggered through a completely separate neural pathway than reflex tears. They are chemically distinct as well, containing higher concentrations of certain proteins and stress hormones. This is normal physiology and not a medical problem, though people who find themselves crying very frequently or without clear emotional triggers should mention it to a doctor, since changes in emotional lability can sometimes accompany neurological conditions or medication side effects.

What Your Tears Might Reveal

Researchers are increasingly interested in tears as a diagnostic fluid, not just for eye diseases but for conditions elsewhere in the body. Tears are easy to collect non-invasively, and their protein and molecular composition changes in response to various diseases. Biomarker research has identified potential tear-based signatures for eye surface diseases, retinal conditions, and even systemic diseases like cancer and multiple sclerosis.¹⁸ This work is still largely in the research phase rather than routine clinical use, but the idea that a simple tear sample could one day flag diseases well before symptoms appear is an active area of investigation. For now, though, if your eye is leaking, the immediate diagnostic question remains simpler: are you making too many tears, or are your tears not draining properly? That distinction is where treatment begins.