The Watery Eye (Adults)
What is a watery eye?
A watery eye has an excess of tears in it, which may spill-over onto the cheeks. It can affect one or both eyes. A watery eye can be very uncomfortable, interfere with vision, and be socially embarrassing for some people.
What is the normal tear pathway?
As seen in figure 1, the tear pathway is much like a tap and sink. The tear gland (lacrimal gland) is located in the upper outer eyelid, and produces the watery part of the tears (the “tap). Tears wash across the surface of the eye from the outer corner to the inner corner. This washing action is aided by the blinking action of the eyelids. Tears then drain into the “sink”, which begins with tiny holes in the inner eyelids (the puncta). From here they flow through a system of tubes (the canaliculi) and into the tear sac (lacrimal sac) that sits between the eye and the nose. From here they drain into another tube (nasolacrimal duct), and eventually end up in the back of the nose and throat.
This explains why we taste tears in the back of our throat and our nose runs, when we cry.
What causes watery eye?
Watery eyes occur when there is loss of equilibrium between tear production and tear drainage. There are 3 main causes of watery eye:
1.Too much tears produced
This is usually in response to irritation of the eye. Irritation of the eyes leads to “reflex” watering of the eyes. Acute irritation from dirt, smoke, pollution, foreign body or an in-turned eyelash can cause sudden and quick watering. But more long-standing persistent watering is due to chronic causes of eye irritation, which include:
- Dry eye (see separate information sheet on Dry Eye) –dry and irritated eyes will lead to reflex watering.
- Blepharitis (see separate information sheet on Blepharitis) –inflammation of the eyelids will cause irritation and dryness of the eyes, leading to reflex watering.
Dry eyes are one of the commonest causes of watery eye. Watering will be worst in conditions that make the dry eyes worse, such as in windy, dusty, cold environments, and when reading or watching TV.
2.Tear drainage is blocked
This may be due to problems in any part of the tear drainage system, and there are many causes. These include:
- Puncta are blocked or in the wrong position due to malposition of the eyelids
- Canaliculi are blocked from trauma or infection
- Nasolacrimal duct is blocked from narrowing and inflammation with age
3.Tears are not pumped properly across the eye toward the tear drainage system
This is usually due to problems with the eyelids. As we age, the lower eyelids stretch, become lax, and may even turn abnormally inward (entropion) or outward (ectropion). This can lead to reduced pumping action of the eyelids that helps tears move across the eye toward the drainage system.
Many patients with watery eye have more than one of these causes. Your ophthalmologist will comprehensively examine your eyes, eyelids and tear drainage system to determine your causes, and their appropriate treatment.
How do I know that I have watery eye?
Patients with watery eye have one or more of the following symptoms:
- Wet eyes
- Overspill of tears onto the cheeks, requiring constant wiping
- Intermittent blurred vision, which clears with blinking
Watery eyes are often worse in
- Cold, outdoor conditions
- Dry, dusty, windy or sunny conditions
- Whilst reading, watching TV, or computer work
What complications can occur from watery eyes?
Watery eyes can significantly interfere with vision.
Constant wiping of the eyes, eyelids and cheeks can result in redness, irritation and excoriation of the eyes, eyelids and skin of the cheeks.
Watery eyes from obstruction of the nasolacrimal duct (Nasolacrimal Duct Obstruction) can develop excess mucous discharge, and occasionally enlargement of the lacrimal sac (mucocele), which may lead to infection (dacryocystitis) of the tear sac or the eye.
How is watery eye diagnosed?
Most causes of watery eye can be diagnosed in the office by your ophthalmologist.
Dry eye and blepharitis are identified on slit lamp examination.
Lax eyelids and eyelid malposition are also diagnosed on examination.
Obstruction of tear drainage, particularly of the nasolacrimal duct, requires a simple procedure to be performed, called syringing and probing (see later). If your tear drainage is obstructed, and surgery is planned, your nose may also be examined with a fine endoscope to look for any abnormalities and assess your suitability for surgery via the nose.
Sometimes special investigations are required to further define any blockage of the tear drainage system. These include X-rays and nuclear scans, which help determine if you will benefit from surgery.
Syringing and probing
This is a painless procedure that does not require anaesthetic and is performed in the office. It aims to diagnose whether you have obstruction of the tear drainage system, and if so, where and how complete that obstruction is. It involves the insertion of a fine blunt probe connected to a syringe filled with sterile saline. This probe is passed into the puncta and tear sac, and fluid is gently syringed through the probe. If there is any obstruction, fluid will “reflux” back out the eyelids onto the eye. If there is no obstruction, you will taste the fluid as it flows normally into the nose and throat.
Syringing and probing is a DIAGNOSTIC test, not a treatment for blocked tear ducts.
How is watery eye treated?
Treatment depends on the cause of your watery eye.
1.Too much tear production from reflex watering
If your watering is due to dry eyes or blepharitis, these will be treated. This usually involves the use of artificial tears, eyelid scrubs and warm compresses.
Any other irritants causing watering should also be identified and avoided or minimised. For example, wearing wrap-around glasses to protect the eyes from dusty and windy conditions when outdoors.
2.Tear drainage is blocked
Surgery is usually required to treat the different points of blockage of the drainage system. Common surgical procedures for blocked tear ducts include:
This is performed for blockage or narrowing of the puncta. This usually involves a simple enlargement of the puncta with scissors, performed under local anaesthetic
Dacryocystorhinostomy (DCR procedure):
Please see separate information sheet for this