Why does my eye keep watering?

A retired teacher in her seventies came to see me last year, embarrassed by tears that ran down her cheeks every time she went outside. Her optician had given her four different lubricant drops over two years. Her GP had prescribed antibiotic ointment twice. She had been told her tear ducts were probably blocked, but also that her eyes were dry. Both of these things were partly true.

After a careful assessment, we found three small problems contributing to her watering rather than one large one. Treating two of them stopped the tears running down her face. The third was minor enough to live with. She told me afterwards that she had not realised how much of her social life she had been quietly avoiding.

Watery eye, or epiphora, is one of the commonest reasons people come to see an oculoplastic surgeon. It is also one of the most often misdiagnosed, because patients and clinicians tend to assume it is one problem with one fix.

Think of the eye as a sink

The tear system is essentially a plumbing system. Tears are produced by glands above the eye and drained away through tiny holes (the puncta) at the inner corner of each eyelid, then down a duct into the back of the nose. When the system works, you do not notice it.

When the eye waters, it is the same as a sink overflowing. There are four possible reasons, and they often happen together.

1. The tap is on too high. This is reflex tearing, where the eye over-produces tears in response to irritation. The most common cause is, paradoxically, dry eye. When the surface of the eye is dry, the brain triggers a flood of watery tears that the drainage system cannot keep up with. Wind, screen use, and certain medications make this worse.

2. The plug hole is too narrow. The puncta are tiny, and over time they can scar down or close (punctal stenosis). When this happens, even a normal volume of tears cannot drain properly.

3. The downstream pipe is blocked. The duct that runs from the eye into the nose can narrow or block, often with no obvious cause. This is the classical “blocked tear duct” most people have heard of, and it tends to happen more in women in their fifties and sixties. When this happens, tears simply have nowhere to go.

4. The sink shape is wrong. A sink that is the wrong shape will not funnel water towards the plug hole, even if the plug hole is open. The eyelid works in the same way. If the lower lid is loose, sagging, or turned outwards, it cannot scoop tears towards the puncta with each blink. The tears pool and overflow before they ever reach the drain.

Why this matters

Most people who come to clinic with a watery eye have more than one of these problems at the same time. An older patient might have a slightly narrowed punctum, a partly blocked duct, and a loose lower eyelid, with each one contributing perhaps a third of the symptoms.

This is why assessment matters. Without testing each part of the system in turn, it is impossible to know which factor or factors are causing the trouble. A patient who only has their duct unblocked, when in fact the bigger problem is a loose eyelid, will be disappointed with the result. A patient who is given drops for dry eye, when the bigger problem is a narrow punctum, will go on watering.

A proper oculoplastic assessment looks at all four parts of the system. This usually involves a slit-lamp examination of the eyelid position and tone, a check of the tear film and surface of the eye, a look at the puncta, and a syringing test that gently flushes the drainage system to see whether it is open. In some cases I will arrange a dacryocystogram, which is an imaging test that maps the duct in detail.

How treatment works

There is rarely a single cure for watery eye. Treatment is aimed at whichever part or parts of the sink are at fault.

• For evaporative dry eye and reflex tearing, the answer is usually lubricants, lid hygiene, and sometimes treatment of the meibomian glands in the eyelids.
• For a narrow punctum, a small office procedure can open it up. In some cases a tiny plastic tube is left in place for a few weeks to keep it open.
• For a blocked duct, the standard treatment is a dacryocystorhinostomy (DCR). This creates a new drainage pathway from the eye into the nose, bypassing the blockage. It is one of the most reliable operations in oculoplastic surgery, with success rates above 90 percent.
• For a loose or malpositioned eyelid, a tightening procedure such as a lateral tarsal strip restores the lid to its proper position so that it can sweep tears towards the drain again.

Sometimes treating one factor reduces the symptoms enough that quality of life improves and no further surgery is needed. Sometimes a staged approach is best, fixing the largest contributor first and reassessing. The more factors involved, the harder it is to achieve complete resolution with a single procedure, and being honest about this from the outset matters.

What to expect

A good outcome does not always mean a completely dry eye. For some patients, going from constant overflow to occasional watering on a windy day is a transformation. We measure this with a questionnaire called the Watery Eye Quality of Life questionnaire (WEQOL), which I helped develop, because the patient’s experience matters more than the technical result.

Most patients I treat for epiphora improve substantially. A small number need more than one operation, and a smaller number have residual watering despite everything we do. Knowing this in advance helps people make informed decisions.

When to see a specialist

If your eye has been watering for more than a few months, if drops have not helped, or if the watering is interfering with reading, driving, or social life, it is worth seeing an oculoplastic surgeon. Watery eye is rarely dangerous, but it is wearing, and a careful assessment is usually the first step towards real improvement.