Watering From the Eyes
The eyes may water for two reasons: increased production of tears and decreased flow of tears.
To understand better how the tear production and outflow system works, a short note on anatomy is useful. Let us first consider the analogy of the eye's tear production and drainage system with a common wash basin. Water comes from an overhead tank, via pipes to the tap, into the basin, and the outflow is via the drainage hole in the basin into the drain.
The same system partially applies to the eye. The tears are formed in the lacrymal gland which is lodged in a recess in the bone under the upper outer corner of the base of the upper lid. The tears are led down by a row of ducts to the eye. The outflow from the eye is by 2 little holes (called puncta) in the upper inner and lower inner corners of the eyelids. The outflow then goes to a little sac lodged in the bone at the inner base of the lower lid and then via a bony canal to open inside the nose. Thus, when a person cuts onions, the eye waters and the nose sniffs.
Increased production can be due to emotional factors like sorrow or grief. It can also be caused by irritation of the eyeball due to smoke, wind or dust. Alternatively, any inflammation or infection in the eye causes an increase in tears.
Decreased outflow is usually because of a partial or complete blockage at the punctum, the sac, or at the outlet at the back of the nose.
Blockage at the punctum is common in old age because of narrowing following any continuous low-grade irritation. The punctum may also be blocked by a foreign particle or even a hair.
The blockage at the sac is either due to a direct chronic infection of the sac because of nose infection or a secondary infection caused by some disease process in the nose.
Watering from the eyes is usually checked by: (a) looking at the puncta under a microscope to see if the openings are clear; (b) pressure on the sac at the inner angle of the eye tells us if there is any blockage below; (c) Examining the nose to be sure there is no disease process.
If all three are clear, the next step is syringing. A blunt needle is gently put in the punctum and salt water injected. It causes no pain. If the patient swallows and says he can taste salt water, the tract is clear. If there is an obstruction, it may be cleared by putting in a blunt, smooth, and flexible silver wire, the process being called "probing". This often succeeds in opening up the obstruction.
Watering from the eyes is harmless and so undue heed must not be paid to it. Though it needs a careful examination to exclude any infection anywhere it is comparatively safe. Unless the watering is excessive and trickles out of the eye, more often than not, your eye doctor may not advise you to have anything done. However if the sac becomes repeatedly inflamed, or the watering is unremittent and does not respond to simple procedures, a bypass surgery may be indicated.