Watery Eyes: Why They Happen and What Actually Helps

Watery eyes (epiphora) are a common and often frustrating problem. Tears may well up and blur your vision, run down your cheeks when you go outside, or leave you dabbing your eyes during meetings. Sometimes the cause is obvious, such as a cold wind or hay fever season. At other times it is puzzling, particularly when you are told that your watery eyes are actually caused by dryness.

In simple terms, eyes water for one of two reasons: either they produce too many tears, usually as a reaction to irritation, or the tears cannot drain away properly. This article explains the most common causes in adults and babies, how to tell them apart, what you can do at home, what treatments are available, and when watery eyes need medical attention.

How tears are made and drained

Tears are produced continuously in small amounts to keep the surface of the eye moist. The main source is the lacrimal gland, which sits under the outer part of the upper eyelid, with smaller glands in the eyelids contributing mucus and oil. Each blink spreads tears across the eye and pumps them toward the inner corner.

At the inner corner of each eyelid there is a tiny opening called a punctum. Tears drain through these openings into small channels (canaliculi), then into the tear sac and down the nasolacrimal duct into the nose. That is why your nose runs when you cry. If tear production suddenly increases beyond what the drainage system can handle, or if any part of this drainage pathway is narrowed or blocked, tears spill over onto the cheek. For more on the structures involved, see our guide to the anatomy of the eye.

Cause 1: dry eye and reflex tearing

It sounds contradictory, but dry eye is one of the most common reasons for watery eyes. When the tear film is unstable or evaporates too quickly, the surface of the eye becomes irritated. The eye responds by producing a flood of reflex tears. These reflex tears are mostly water and lack the oily and mucous components that keep tears on the eye, so they spill over quickly without fixing the underlying dryness.

Typical features include watering that is worse in wind, cold air, air conditioning or after screen use, along with grittiness, burning or a feeling of something in the eye. Many people with this pattern also have meibomian gland dysfunction, in which the oil glands along the eyelid margins do not work properly.

Treating the dryness usually reduces the watering. This may involve artificial tears, warm compresses and eyelid hygiene, regular screen breaks with full blinks, and avoiding air blowing on the face. Our guide on dry eye disease covers this in detail.

Cause 2: allergies

Allergic conjunctivitis occurs when the eye's surface reacts to allergens such as pollen, dust mites, pet dander or mould. The release of histamine causes itching, redness, swelling and watering. Seasonal allergies tend to come with sneezing and a runny nose, while year-round allergies are often linked to indoor allergens.

Itching is the hallmark of eye allergy. Helpful measures include avoiding triggers where possible, cool compresses, washing the face and hair after being outdoors in pollen season, and over-the-counter antihistamine or mast cell stabiliser eye drops. A pharmacist or doctor can advise which product is suitable. Our guide on eye allergies explains the options.

Cause 3: eyelid problems

Blepharitis

Blepharitis is a common, often long-term inflammation of the eyelid margins. Crusting at the base of the lashes, red lid edges and blocked oil glands disrupt the tear film, causing irritation and reflex watering. Regular eyelid hygiene, with warm compresses and gentle cleaning of the lid margins, is the mainstay of treatment.

Lid position problems

With age, the tissues of the lower eyelid can become lax. The lid may turn outward (ectropion), so the punctum no longer sits against the eye and tears cannot enter the drainage system. Alternatively, the lid may turn inward (entropion), so the lashes rub against the eye, causing irritation and watering. Facial nerve weakness, such as after Bell's palsy, can also weaken the blink and the tear pump. These problems are often treatable with minor surgery to reposition or tighten the eyelid.

Ingrowing eyelashes

Lashes that grow toward the eye (trichiasis) scratch the surface and trigger watering. They can be removed, and recurrent cases can be treated more permanently.

Cause 4: infections and inflammation

Infectious conjunctivitis (pink eye) causes redness, watering and discharge. Viral conjunctivitis typically produces watery discharge and often follows a cold, while bacterial conjunctivitis tends to produce thicker, yellow or green discharge with lids stuck together in the morning. Viral infections usually settle on their own over one to three weeks, while bacterial infections may be treated with antibiotic drops if a doctor considers them necessary.

More serious causes of watering with redness and pain include inflammation or infection of the cornea (keratitis), particularly in contact lens wearers, inflammation inside the eye (uveitis), and foreign bodies. These need prompt assessment.

Cause 5: blocked tear ducts in adults

A blocked nasolacrimal duct prevents tears from draining into the nose. In adults, this often develops gradually with age due to narrowing of the duct, but it can also follow infections, injuries to the nose or face, sinus problems or certain treatments. The main symptom is persistent watering of one or both eyes, often worse outdoors, with tears overflowing onto the cheek. If tears stagnate in the tear sac, it can become infected (dacryocystitis), causing a painful, red swelling at the inner corner of the eye and discharge.

An eye doctor can test whether the drainage system is open, for example by gently flushing saline through the punctum to see if it reaches the nose. Depending on the location and severity of the blockage, treatment options include probing or widening the channels, or a surgical procedure called dacryocystorhinostomy (DCR), which creates a new drainage route from the tear sac into the nose. Infections of the tear sac are treated with antibiotics prescribed by a doctor.

Cause 6: blocked tear ducts in babies

Watery or sticky eyes are very common in newborns. Many babies are born with a tear duct that has not fully opened, usually because a thin membrane at the lower end of the duct has not yet broken down (congenital nasolacrimal duct obstruction). Signs include persistent watering, tears running down the cheek even when the baby is not crying, and sticky, crusty eyelashes, especially after sleep.

The good news is that the majority of cases resolve on their own during the first year of life. Parents can help by:

• gently cleaning the eyelids with cotton wool moistened with cooled boiled water, wiping from the inner corner outward and using a fresh piece for each eye;
• performing gentle massage over the tear sac, at the side of the nose near the inner corner of the eye, if shown how by a health professional;
• watching for signs of infection.

If watering persists beyond about the first year, the eye doctor may recommend a simple procedure to probe and open the duct. Babies with persistent watering, a swelling at the inner corner, or a red eye should be seen by a doctor. Watering combined with light sensitivity and an enlarged or cloudy-looking eye is rare but requires urgent assessment, as it can be a sign of congenital glaucoma. Our guide to eye health in children has more information.

Other causes

• Environmental irritants: wind, cold, smoke, bright light and chemical fumes.
• Foreign bodies: grit or an eyelash in the eye.
• Medications: some medicines, including certain chemotherapy drugs, can cause watering or narrow the drainage channels.
• Thyroid eye disease and facial nerve problems can affect lid closure and the tear film.
• Emotional tearing and yawning are normal reflexes.

What you can do at home

• Protect your eyes outdoors: wraparound glasses or sunglasses reduce wind-induced watering.
• Look after your eyelids: warm compresses and lid cleaning help blepharitis and oil gland problems. See our warm compress guide.
• Use lubricating drops: preservative-free artificial tears can calm a dry, irritated surface that is triggering reflex tearing.
• Manage allergies: reduce exposure to triggers, and consider antihistamine eye drops after advice from a pharmacist.
• Blink and take breaks: particularly during screen work.
• Wipe gently: dab tears from the outer corner toward the inner corner with a clean tissue. Frequent wiping that pulls the lower lid outward can worsen lid laxity over time.
• Practise good hygiene: wash hands, avoid rubbing your eyes and do not share towels if infection is possible.

Medical treatments

Treatment depends on the underlying cause. An optometrist or ophthalmologist will examine the eyelids, the surface of the eye and the drainage system to identify it.

When to see a doctor

See an optometrist or doctor if watering persists for more than a few weeks, affects your daily life or vision, is accompanied by discharge or crusting, occurs with a sagging or turned eyelid, or if you notice a lump or swelling near the inner corner of the eye. Babies with persistent watering should be checked by a health professional.