Introduction
Watering eyes are a common problem, especially in older people over the age of 60, and in babies (0-12 months of age). It can occur in one or both of the eyes.
Your eyes need to produce a certain amount of tears so they stay moist and comfortable. A gland, called the lacrimal gland, produces the tears, which are then spread over your eyes when you blink. The excess tears will then usually drain away down tiny channels on the inside of the eyes, into a tear 'sac', and finally down a tear duct, and into your nose.
When tears begin to roll down your cheeks without explanation (you are not crying because you feel emotional), it can cause a lot of discomfort and concern.
Causes
Your eyes produce extra tears when something irritates them, to help wash away the 'irritant'. Irritants include fumes, an infection such as conjunctivitis, a scratch, a piece of grit, or an inwardly growing eyelash (also called an entropion).
The most common cause of watering eyes is a blocked or narrowed tear duct, which can be due to inflammation (swelling). Tears can then remain in the tear sac and become infected. You will know if your tear sac is infected because your eye will have a sticky discharge, and you may notice a swelling on the side of your nose, near your eye.
Babies are often born with a closed tear duct, but this will often resolve itself without any treatment within a few weeks.
In other cases, watering eyes can be caused by the lower eyelid turning outward away from your eye. This is called an ectropion. If this happens, your tears are not able to drain away properly.
Finally, it is possible that your tears have an unusual lipid (fat) content, which means that they cannot spread across your eye evenly. This then leads to dry patches on your eye that become sore, which then causes extra tears to be produced.
Diagnosis
If you have watering eyes, your GP may be able to diagnose the cause quite easily, for example, if you have an infection or an inwardly growing eyelash. If the cause is not obvious, you may be referred to an eye specialist (ophthalmologist).
The eye specialist will be able to examine your eyes under a local anaesthetic (you are awake during the process but do not feel any pain) to check for any possible blockages. If there is a blockage, they may suggest that you have a dye injected into the tear duct, so that an X-ray can be done. This X-ray will then show up exactly where the blockage is.
Treatment
Treatment for watering eyes depends on the cause, and whether you feel it bothers you very much. Some people find that they only have a mild case and do not need any treatment. Watering eyes in babies often resolve themselves without treatment within a few weeks.
Inwardly growing eyelashes and pieces of grit in the eye can be removed. Infections can be treated with prescription eye drops. An ectropion (outward turning lower eyelid)can be corrected with a minor operation.
It is also possible to have an operation to treat a blocked tear duct. A common procedure is called DCR (dacrocystorhinostomy). This means that a new channel is created from the tear sac to the inside of your nose. This channel allows the tears to bypass the blocked part of the tear duct.