Epiphora - Causes of watering eyes

Watering eyes usually occur if too many tears are produced or if they cannot drain away properly.

Blocked tear ducts

Tear ducts are the passageways through which excess tears drain away. If they become blocked, it can cause your eyes to water.

In adults, this is usually the result of age, or sometimes inflammation, compression or injury.

A blocked tear duct can mean your tears will be unable to drain away and will remain in the tear sac. If this happens, the tears in the tear sac may become stagnant and a sticky liquid (mucus) may discharge through the tear duct opening into the eye.

You may also develop a swelling on the side of your nose, next to your eye, which is called a mucocele. If it becomes infected, it can cause a painful abscess to develop just below your eye which may need to be treated with antibiotics and possibly surgery.

Occasionally, the canaliculi (the narrow drainage channels on the inside of your eyes that lead into the tear ducts) can become blocked. This can be caused by inflammation or scarring due to a viral infection, or injury.

In addition, the lower eyelid can sometimes turn out (ectropion), causing the openings to the tear ducts to move away from the eye and making it difficult for the tears to reach them.

Blocked tear ducts in babies

Babies are sometimes born with under-developed tear ducts. The tear ducts can be completely or partially closed (congenital nasolacrimal duct obstruction) and can cause the baby’s eyes to water. Most blocked tear ducts in babies get better on their own before the baby is one year old.

In some cases, a blocked tear duct can lead to eye infections (conjunctivitis) in babies. Their eye may be red and have a sticky discharge coming from it. Take your baby to see your GP if you think they might have an eye infection.

Poor tear pump

A good blink ensures tears drain properly into the tear duct. People with a weak blink, for example due to a condition called Bell’s palsy (a type of facial paralysis) have problems with this which contributes to their watery eyes.

Excess tears

There are several reasons why you might produce excess tears.

Irritation

Excessive tear production (reflex tearing) is usually the result of eye irritation. Extra tears are needed to wash away the substance irritating your eye.

Problems that can cause extra tears to be produced include:

chemical irritants, such as onions or fumes
an eye infection, such as conjunctivitis
an allergy
an eye injury, such as grit that becomes lodged in the eye
an inward-turning eyelid (entropion) - see eyelid problems for more information
an outward-turning eyelid (ectropion)

Abnormal tears

Tears are made up of different substances including water, proteins and oils. If your tears have an abnormal oil content, they may not be able to spread evenly across your eye. This can result in dry patches on your eyes which become sore, causing extra tears to be produced.

If you have abnormal tears and dry patches, you may have dry eye syndrome, which can cause your eyes to become red, feel gritty and sometimes water excessively.

Blepharitis

Blepharitis causes the rims of your eyelids to become inflamed, leading to stinging or itching eyes. This can cause reflex tearing. It can also affect how your tears are spread across the surface of your eyes and lead to watering eyes.