The tears are produced in glands situated at upper part of the cavity of the eye, and opening by ducts upon the surface of the conjunctiva between the eyeball and upper lid. The office of the tears is to keep the parts over which they are diffused moist and polished, and to preserve their transparency.

The movements of the lids spread the tears uniformly over the eyeball; they are then conducted off through the lachrymal canals, and are finally discharged into the nasal passages. The lachrymal glands are occasionally subject to inflammations.

In some affections there is an over secretion of tears, and in others a deficiency, and a consequent dryness of the eyes. In cases of the former, the eyes should be carefully examined for foreign bodies or inverted eyelashes. If the irritability apparently results from an impoverished and debilitated state of the system, tonics should be given. When the secretion of tears is scanty and the eye dry in consequence, glycerin should be occasionally applied.

Fistula lachrymalis signifies an ulcerous opening in the lachrymal sack. It is the ordinary consequence of obstruction of the nasal duct, the symptom of which is a persistent watering of the eye. Inflammation follows this stoppage, resulting in an abscess, which bursting causes the fistulous aperture from which the name of the affection is derived.

The treatment of this condition demands the skill of an experienced surgeon.