d this out themselves, and the tendency is
rather to hold the book too near, for the nearer the object to the
eye, the larger its picture upon the retina, or back eye wall. But
here we encounter another danger. The nearer the object the eyes are
concentrated upon, the greater the muscular effort necessary; so that
by holding the book too near, the labor of reading is greatly
increased, and the long persistence in such a habit is likely to
produce weak eyes, and may, in some instances, lead to real
near-sightedness. When children are observed to have acquired this
habit and cannot be persuaded out of it, they should always be taken
to a physician skilled in the treatment of the eye for examination and
advice. A little attention at such a time may save them from a whole
lifetime of trouble with their eyes. Of course, the larger the print,
the farther it may be held from the eyes.

POSITION.

2. The position of the person with regard to the light should be so
that the latter will fall upon the page he is reading, and not upon
his eyes. It is generally considered most convenient to have the light
shine over the left shoulder, so that in turning the leaves of the
book, the shadow of the hand upon the page is avoided. It is not
always possible to do this, however, and, at the same time, to get
plenty of light upon the page. When one finds himself compelled to
face the light in reading, or in standing at a desk bookkeeping, he
should always contrive to shade his eyes from a direct light. This may
be done with a large eye shade projecting from the brow. A friend of
mine, a physician, is very fond of reading by a kerosene lamp, the
lamp being placed on a table by his side, and the direct light kept
from his eyes by means of a piece of cardboard stuck up by the lamp
chimney.

PROPER LIGHT.

3. The illumination should always be sufficient. Nothing is more
injurious to the eyes than reading by a poor light. Many persons
strain their eyes by reading on into the twilight as long as they
possibly can. They become interested and do not like to leave off.
Some read in the evening at too great a distance from the source of
light, forgetting that the quantity of light diminishes as the square
of the distance from the source of light increases. Thus, at four
feet, one gets only one-sixteenth part of the light upon his page that
he would at one foot. It is the duty of parents and others who have
charge of children to see to it tha