The tear film protects the eye from infection and allows clear vision. It constantly replenishes itself, washing across the front of the eye, entering the inner corner of the eye, and passing downward into the tear sac and through a vertical passage (the tear duct) to the back of the nose.
Babies often have tear duct blockages which can usually be cleared with daily massaging of the side of the nose.
In adults, if the tear duct does not open on its own or with the aid of massage, it may be necessary for your ophthalmologist to unblock it using a small probe. This is a minor procedure lasting no more than twenty minutes, which resolves the problem, 90% of the time, however sometimes a second probing is needed.
Symptoms are usually when tears flow onto the cheek. If the tears lead to crusting, there maybe infection.
Persistent problems should be seen by an ophthalmologist to ensure there is no physical blockage of the duct.