the intra-ocular vessels, is not usually attended with any lacrymation.
When the balance is on the other side, and the eye becomes too soft,
there is a greater tendency to lacrymation. Finally, there are
numerous morbid states and structural alterations of the eyes,
and even terrible inflammations, which may be attended with little
or no secretion of tears.

It also deserves notice, as indirectly bearing on our subject,
that the eye and adjoining parts are subject to an extraordinary
number of reflex and associated movements, sensations, and actions,
besides those relating to the lacrymal glands. When a bright
light strikes the retina of one eye alone, the iris contracts,
but the iris of the other eye moves after a measurable interval of time.
The iris likewise moves in accommodation to near or distant vision,
and when the two eyes are made to converge.[23] Every one knows how
irresistibly the eyebrows are drawn down under an intensely bright light.
The eyelids also involuntarily wink when an object is moved near the eyes,
or a sound is suddenly heard. The well-known case of a bright light
causing some persons to sneeze is even more curious; for nerve-force
here radiates from certain nerve-cells in connection with the retina,
to the sensory nerve-cells of the nose, causing it to tickle;
and from these, to the cells which command the various respiratory muscles
(the orbiculars included) which expel the air in so peculiar a manner
that it rushes through the nostrils alone.

To return to our point: why are tears secreted during
a screaming-fit or other violent expiratory efforts?
As a slight blow on the eyelids causes a copious secretion
of tears, it is at least possible that the spasmodic contraction
of the eyelids, by pressing strongly on the eyeball, should in