Watery eye due to nasolacrimal duct obstruction

There are many causes of watery eyes, which is why a successful treatment depends on a thorough initial examination by a specialized ophthalmologist. A simple way to understand this condition is by classifying tearing into two categories: one caused by abnormalities in the tear drainage system, and the other by excessive tear production.

Watery eyes can result from issues within the lacrimal system, which may be affected at any point from the beginning of the canaliculi to the nasolacrimal duct. Sometimes, the system appears anatomically open during examination but fails to drain tears properly. This is referred to as functional epiphora, meaning the drainage system’s function—rather than its structure—is impaired.

Newborns may occasionally present with a low obstruction of the nasolacrimal duct. This is usually due to an immature drainage system and, in most cases, resolves spontaneously before the age of one.

In adults, the most common issue with the lacrimal system occurs in the nasolacrimal duct. For reasons that remain unclear, the duct may gradually narrow with age and eventually become completely blocked. This occurs more frequently in women over the age of fifty. When the nasolacrimal duct becomes narrowed, it not only causes tearing but may also lead to infection, characterized by pain, redness, and sometimes discharge in the area of the lacrimal sac.

When a patient with watery eyes has a normal lacrimal drainage system, other potential causes must be considered. In such cases, it is important to carefully examine the ocular surface, as any issue in this area can cause irritation and trigger reflex tearing.