Watering eyes occur if too many tears are produced or if they cannot drain away properly.
The problem can affect anyone, but it's most common in young babies and people older than 60. It can cause blurred vision, sore eyelids and sticky eyes.
See your GP or optician if you have persistent watering eyes or any lumps or swelling around your eyes.
Glands in the eyelids (Meibomian glands) normally secrete an oily substance that slows the evaporation of tears between blinks.
When these glands don't function properly, known as Meibomian gland dysfunction (MGD), it can result in dry patches on your eyes. These become sore, and extra tears are produced as a reflex. This is the most likely cause of watering eyes.
Other problems that can cause extra tears to be produced include:
Your GP may refer you to an optometrist (eye specialist) for an examination, if no obvious reason for your watering eye can be found.
If necessary, you may then be referred to an ophthalmologist (eye surgeon) for further investigation.
An ophthalmologist will look for blockages in your tear ducts, using local anaesthetic eye drops to help reduce any discomfort. This involves inserting a tiny probe into the narrow drainage channels on the inside of your eyelid to determine whether they are blocked. Fluid may also be injected into your tear duct, to see whether it comes out normally.
Another test involves placing a drop of special dye in each eye. If there is a significant amount left in your eyes after five minutes of normal blinking, your tear ducts may be blocked.
Scans of your tear ducts may sometimes be carried out. These can involve either injecting or placing special dyes into the tear ducts and then taking X-rays or other scans to help pinpoint the location of the blockage.
If you're producing extra tears as a result of dry eye syndrome , you may be offered lubricating eye drops and advised to avoid activities that aggravate your symptoms.
Medication may be needed if the cause is an allergy or infection, and surgery may be needed if a tear duct is blocked.
If watering eyes aren't interfering with your life, you may choose not to have treatment.
Read more about treating watering eyes .