f
feet the eye ought to see is written as the denominator of the
fraction; the distance the eye can see clearly is the numerator. If the
child's card reads, "Right eye 10/10, left eye 10/20," it means that
the right eye sees without conscious strain the distance it is intended
to see, while the left eye must be within ten feet to see what it ought
to see twenty feet away.

The practical steps for a teacher to take in making eye tests are:

1. Scrutinize the faces for a strained or worried expression while
reading or writing, for squint eyes, for unnatural positions, and
for improper distances (more or less than nine inches) from eye to
book.

2. Select for first tests the children who obviously need
attention and will be obviously benefited. Use the eye test to
help trace the cause of headaches, nervousness, inattention.

3. Let the children mark off the distances with a foot rule and
chalk, going as high as twenty. Be sure to get the best light in
the room.

4. Start all children on the ten-foot line. If a child cannot read
at ten feet the letter which should be seen at that distance, move
the child forward, have it step forward and backward, and note the
result carefully. It is better to have ten separate letters of
exactly the right size and the same size than a row of letters on
one card, as in the Snellen test, otherwise memory will aid the
eye, or, as happened recently, a whole class may agree to feign
remarkable nearsightedness or farsightedness by confusing letters
learned in advance from the card. If the Snellen card is used, and
if it is more convenient to have both child and card stationary,
satisfactory results will be obtained by having the child read
from large letters down as far as he can see.

5. Have the child read from right to left, from left to right, or
skip about so that memory cannot aid the eye.

6. Test each eye separately. I was twenty-five years old before I
learned that my left eye did practically all of the close sight
work. A grown woman discovered just a few days ago that she was
almost blind in the left eye; when she rubbed the right one while
reading she was shocked to find that she could see nothing with
the left eye.

7. If the card is stationary and the child moved, and if only one
size of the letter is used, put in the denominator the number of
feet at which the normal eye should see clearly, and in the