Tears are very important to the health of our eyes. However, too many tears, or watery eyes, is not just frustrating and perhaps embarrassing – they may also cause vision problems.
Watery eyes are commonly caused by the eye producing too many tears and/or poor drainage of the tears from the eye.
- Producing too many tears may be a response to eyelid inflammation, allergy or irritation.
- A range of treatments are available depending on the cause.
- Poor tear drainage can be due to a physical problem with the eye's tear ducts and may require surgery.
Causes
The main reasons for watery eye problems are:
- overproduction of tears
- poor drainage of tears
- a combination of the above.
How are tears produced and drained?
The eye's tears are composed of three layers: oil, water and mucous. The oily layer is produced by the meibomian glands which line the edge of the eyelids. The lacrimal gland, which lies just below the eyebrow produces the watery layer. The third layer, comes from microscopic goblet cells in the conjunctiva.
To keep your eyes comfortable, a small volume of tears is continually produced. When your eyes are irritated or when you cry, a greater volume of tears are produced from larger glands near the outer corner of the eye.
Some of the tear fluid evaporates from the surface of the eye. The rest drain via small canals from the upper and lower eyelids near the nose to a bony canal (the nasolacrimal duct) and on to the nose. This is the reason you need to blow your nose when you cry!
Overproduction of tears
Overproduction of tears is usually due to irritation of the surface of the eye. There are many potential causes but the commonest include:
- eyelid inflammation
- cold, windy weather
- allergy
- light sensitivity and glare problems
Rarer causes include:
- infection
- floppy eyelids
- ‘crocodile tear syndrome’ (which can occur after a person has had Bell’s palsy, a type of facial paralysis)
Treatment of tear overproduction involves identifying and relieving the cause. The treatments are usually non-surgical and may need to continue in the long term to control the underlying problem.
Impaired tear drainage
Again, there are many potential causes for impaired tear drainage. They include:
- Looseness of the lower eyelids with misplaced tear drainage openings (puncta) or poor tear pump function.
- Narrow tear drainage openings.
- Partial or complete blockage of the nasolacrimal duct (the bony canal that drains tears from the eyes).
Treatment of poor tear drainage is usually surgical. This may include:
- eyelid tightening
- opening of the puncta (tear drainage openings)
- surgery to remove an obstruction
Surgery usually works well in improving watering problems due to poor tear drainage.
Infants
Occasionally, babies have a watery eye and this is usually due to a blocked nasolacrimal duct. In most cases, this comes right on it's own by 12 months of age. If the problem fails to improve, tell your family doctor and they can refer you to an eye specialist.
By passing a fine probe along the tear drainage pathway under general anaesthesia, this problem is easily fixed in more than 90% of cases.
Learn more
For further information contact your optometrist or ophthalmologist for individual assessment.
Watery eyes Eye Institute Auckland NZ
Watery eye Auckland Eye
Watery eyes Mayo Foundation for Medical Education and Research, 2012
Watery eyes – when to see a doctor Mayo Foundation for Medical Education and Research, 2012