Unilateral Watering Eye

Watering eyes from a narrowed or obstructed tear drainage duct are more common as we get older. The drainage duct progressively narrows with time and tearing is experienced. Tears can blur the vision, make you look as if you are crying, and irritate the skin. Watering eyes also smudge makeup. Glasses can get smattered with tears. Watering eyes are very annoying for the patient. Sometimes a young adult will develop a troublesome watering eye. This can be from a unilateral obstructed nasolacrimal duct, the main tear drainage duct from the eye to the inside of the nose.
A lacrimal stone can cause a unilateral watering eye in a young person. Every so often I see a young patient who is aged between about 25 and 45 who has experienced a relatively sudden onset of a unilateral watering eye. There can be a little bit of discharge at the corner of the eye, and they may often tell me that they had had this blockage before, that it was flushed through by their doctor and then they have had no problem since, until this new attack. Lacrimal stones affect a small group of people. They have lacrimal gravel or lacrimal stones within the lacrimal sac, and by washing through the tear duct system, the gravel or stones can be flushed through and drain down into the nose, after which the tears will start to drain normally or near normal again.
Some patients have little attacks of lacrimal gravel or stones about once a year for two or three years, and gradually there can be some inflammation resultant fibrosis, and they will develop a narrowing of the junction between the lacrimal sac and the duct and get a more permanent watering eye which requires surgery. I have even seen stones emerging from the lacrimal duct on nasal endoscopy, and once that stone, which can be quite soft has passed, then their watering eye goes away. Although not a very well known cause of a watering eye, benign lacrimal stones or gravel cause significant pathology and morbidity for the patient. Many patients with gravel or stones can benefit from repeat washouts over some years, but a small number end up with real internal duct narrowing and require a drainage operation called a dacryocystorhinostomy (DCR).
If you have a unilateral watering eye, I would be pleased to help by investigating it, and it may well prove to be a simple lacrimal stone. Other causes of the unilateral watering eye include trauma, tumour, asymmetrical inflammation and fibrosis called primary acquired nasolacrimal duct obstruction. Investigations include examination in the clinic, sac wash out, nasal endoscopy and possibly additional tests such as special X-ray or lacrimal scintigraphy