Three main causes of a watering eye
There are three main causes of a watering eye which we must distinguish between to choose the right treatment for you.
- Hypersecretion: This is an excess or reflex production of tears as a reaction to either a dry eye, to a corneal foreign body or conjunctivitis or blepharitis.
- Epiphora: This is the result of reduced tear outflow, i.e. defective tear drainage.
- A combination of both hypersecretion and epiphora: For instance, when there is eyelid malposition with inflammation. This will mean that there is reflex tearing because of the inflamed eyelid, but also the malpositioned eyelid cannot catch the tears and drain them down the tear duct.
One of the commonest causes of hypersecretion is blepharitis, meibomian gland dysfunction (MGD) and dry eyes.
Paradoxical symptoms of watering occur with blepharitis and dry eyes and are usually bilateral, worse in a dry, smoky atmosphere or air-conditioning and worse towards the end of the day.
Causes of unilateral lacrimation or hypersecretion include corneal abrasions and keratitis. For instance marginal keratitis, which occurs with blepharitis, or anything which is irritating the cornea to cause secondary watering. For this reason, I have to examine the external eye, the eyelids, the conjunctiva and the cornea to exclude blepharitis, dry eyes, conjunctivitis and keratitis.
Blepharitis is exceedingly common as are dry eyes. Both conditions are increasing in prevalence with younger people getting blepharitis because of screen use.
I have to look at the level of the tear film called the tear meniscus and also whether there are flakes or debris along the lashes and whether there is any staining of the surface of the eye with a dye called fluorescein. I have to look at the extent of the lid blink; whether it is complete or partial.
Often the history will tell me whether the patient has a dry eye or watering eye because typically dry eyes are very bad on waking. They feel dry, and then there can be an enormous gush of water particularly if the eye is rubbed and dry eyes can cause a feeling of wetness or water towards the end of the day.
In contrast, if there is a watering eye due to tear outflow obstruction or to narrow, then this is often worse in the mornings and worse outside in cold weather. Having the skills to detect whether there is hypersecretion, epiphora or a combination thereof is part of my training as an oculoplastic surgeon.
If you have watering eyes, you should consider seeing either an external eye disease ophthalmologist, who can look and see whether you have got blepharitis/dry eyes, or an oculoplastic surgeon who can also look and see if you got blepharitis and dry eyes. Also, they can examine the tear outflow system and see whether there is any abnormality of the eyelid function and the tear duct lumens.