(2) it does not show unconscious eye strain due to successful
accommodation. But it will discover a great part of the children who
most need care. Sooner or later, too, inflammation of the eyelids, due
to external causes, will affect the nerves of the eye and their power
to conceal by accommodation the eye's defects. Just as we unconsciously
open the mouth when a cold stops up the nose, the eye adapts itself to
our needs without our realizing it. We expect it to see. It sees. If
our eyes are not made alike, they do their best to work together. Like
a good team of horses, the slow one hurries, the fast one holds back a
little. But if one eye is 10/15 and the other 10/10, they will both be
unnatural and strained if both read the same type. The effects of this
strain frequently upset the stomach before the eyes rebel. I learned
that I needed eyeglasses after a case of protracted indigestion, first
diagnosed as "nervous" and later traced to eyes. Thousands of
upper-grade children and college students are dieting for stomach
trouble that will last until the eyes are relieved of the undue and
unrecognized strain. To prove the influence of eye strain on
indigestion, persuade some obstinate parent to wear improperly focused
glasses for a day; she will then be willing to have her child's eyes
attended to.

It is unfortunate that the eyes will overwork without protesting. For
years many persons suffer without learning that their eyes are unlike,
or, as often happens, that one eye does all the close range work. Even
when being tested, eyes will seem to see easily what requires a great
effort of "accommodation." To prevent this self-deception skilled
oculists do not trust the eye card, but put a drug in the eye that
benumbs the muscles of accommodation. They cannot contract or expand if
they want to. The oculist then studies the length of the eye and the
muscle of accommodation. With this absolute knowledge of how each eye
is made he knows what is wrong, exactly at what angle light enters the
eye, whether objects are focused too soon or too late, exactly what
kind of eyeglasses or what operation upon the eye is needed to enable
it to do its work without undue straining or accommodation. So
unconsciously do the eyes accommodate themselves to the work expected
of them that not infrequently a child with seemingly perfect sight may
be more in need of glasses than the child with imperfect sight.
Practically, however, it is out of the qu