"The light of the body is the eye." Of all our senses, sight, hearing,
touch, taste, and smell, the sight is that which seems to us the most
important. Through the eye, the organ of vision, we gain more
information and experience more pleasure, perhaps, than through any or
all our other organs of sense. Indeed, we are apt to depreciate the
value of our other senses when comparing them to the eyesight. It is
not uncommon to hear a person say, "I would rather die than be blind."
But no one says, "I would rather die than lose my hearing." As a
matter of fact, the person who is totally blind generally appears to
be more cheerful, happier, than one who is totally deaf. Deaf mutes
are often dull, morose, quick tempered, obstinate, self-willed, and
difficult to get along with, while the blind are not infrequently
distinguished for qualities quite the reverse. It is worthy of remark
that the eye is that organ of sense which is most ornamental as well
as useful, and the deprivation of which constitutes the most visible
deformity. But it is unnecessary to enter into a comparison of the
relative value of our senses or the relative misfortune of our loss of
any one of them. We need them all in our daily struggle for existence,
and it is necessary to our physical and mental well-being, as well as
to our success in life, that we preserve them all in as high a degree
of perfection as possible. We must not lose sight of the fact that all
our organs of sense are parts of one body, and that whatever we do to
improve or preserve the health of our eyes cannot do harm to any other
organ. We shall be able to "take care of our eyes" more intelligently
if we know something of their structure and how they perform their
functions. The eye is a hollow globe filled with transparent material
and set in a bony cavity of the skull, which, with the eyelids and
eyelashes, protect it from injury. It is moved at will in every
direction by six muscles which are attached to its surface, and is
lubricated and kept moist by the secretions of the tear gland and
other glands, which secretions, having done their work, are carried
down into the nose by a passage especially made for the purpose--the
tear duct. We are all familiar with the fact that our eyes are "to see
with," but in order to be able to take care of our eyes intelligently,
it is necessary to understand as far as possible how to see with them.