About one-eighth of an inch from the internal angle of the eye, a small
projection is to be seen on the margin of the lid. In the center of this
is a tiny opening through which the tears as they collect in the eye are
led away through two small canals to the lachrymal sac in the upper part
of the nose. The lachrymal gland, which secretes the tears, or water, of
the eye, is situated above on the outer side of the eyeball, between it
and the bones of the orbit. The lachrymal gland is constantly secreting
tears, which are carried by narrow ducts to the upper surface of the
eyeball, whence they flow down over the eye, finally being collected at
the inner corner of the eye and passing into the nose through the
lachrymal punctures described above. Under certain circumstances, as
from emotion, a blow, or the irritation of a cold wind, the tear fluid
is secreted faster than it can escape through the punctures, and so
flows over the lids and down the cheeks.