This sense has been endowed by nature with special ability and capacity. The nerves connecting the eye with the brain are eighteen times larger than those of any other sense. Their capacity to impress the brain is therefore many times greater. At the same time nature has duplicated the sense of sight and we have the mind's eye, or the faculty of visualization, by which we can reproduce the visual impression, or picture, of the thing which we have seen. This faculty is one of the important foundations of memory development as you will see in future chapters.
We are probably more conscious of defects in the operation of the sense of sight because of the many opportunities for comparison with others. Children may differ considerably in their vision but any unusual condition should prompt a consultation with a specialist.
Because of the movement possible in this sense organ and the delicate muscles which control it, there is the possibility of improvement by muscular exercise which does not exist in the other senses. The following exercises will strengthen the eye muscles. They should be practiced by persons of all ages. It has been found during operations that some of the eye muscles have been exercised so little that they have become almost incapable of use.
These exercises are simple, and can be practiced at odd moments, that would otherwise be wasted.
First—Move the eye horizontally as far as you can to the left and then to the right. Continue this until there is a feeling of fatigue. No physical exercise should be continued beyond that point.
Second—Move the eyes vertically as far as you can, up and then down, trying to extend the range of vision. Continue this alternately until you feel fatigue.
Third—Roll the eyes from right to left and then from left to right in as large a circle as possible.
These exercises will keep the eye muscles in a healthy condition. See to it that the child does not abuse his eyes; that he does not strain them; always has plenty of light and that it falls upon the page, or work, that he is doing. Do not overlook indications of eye trouble, eye pains, inflamed lids, continued recurrence of styes, blood-shot eyeballs, or pain back of the eyes, all should have the attention of a doctor. "A stitch in time saves nine."
Strive for More Detail
There is the greatest difference in the amount of detail which the eyes of different persons gather from a glance at an object. Some will only see a tree; others in the same time will see a tree with spreading branches, small irregularly shaped leaves, with small black berries and a rough vertically marked bark. Children should be trained to notice as much detail as possible. Development along this line becomes a basis for many other mental operations which will be discussed later on.
Exercise for Detail
Place yourself with the child where you can look out on the landscape. Pick out some object, tell him what it is, and have him look until he finds it. Then let the child pick out some object that he thinks will be difficult for you to find. It may be a bird, a red flower, or a hoop. As he develops pick objects farther away, smaller or partially hidden.
Another Good Exercise
Have the child look at a house and give you all the detail that he can see. Call the child's attention to the things missed so that he sees the reason for making an additional effort. The same exercise can be followed with any object, a tree, an automobile, or an animal. When in the house use a picture on the wall, a table, a book case or a coin. You will find that the longer the child looks at the object the more detail he will see. The aim is to get him to notice and mention the details as quickly as possible. After some practice he will be able to mention them as rapidly as he can speak. This can be made into a competitive game when there are several children. Keep score of the number of the details each can write on a slip of paper in a given length of time.
Training the Eye to Measure
The ability to accurately measure with the eye is a thing that a great many people find very difficult, if not almost impossible. You are continuously finding opportunity to use such an ability. A little conscious effort will work wonders in this regard and children should not be allowed to grow up without being trained to intelligently estimate measurements. In this training begin with larger measurements and from that work to the finer ones as rapidly as the child can progress.
First Exercise
Have the child determine which of two trees in the distance is the closest or use any other objects in the landscape. Walk towards the trees to prove the matter. Point out things of interest to encourage the child's observation of nature.
Second Exercise
Give the child a foot rule and let him become acquainted with its length. Then with his fingers on the table have him indicate the distance which he believes to equal that of the length of the rule. Lay it between the child's fingers. Practice until he knows accurately how long a foot is. At the same time and for variety he can practice with a half foot and an inch. Have him compare objects with a foot rule and determine whether they are longer or shorter. Then let him measure the objects. Allow the child to check the measurements himself, this will increase his definite conception of the length of a foot.
The Game of Measuring
Let the child with his eye, and without a rule, measure the length of the table, of the book case, the side of the room, or the height of a door. Have him do this by eye measurement and not by guess work. Teach him to start at one end and select a point which he judges to be one foot from the end and then to advance the eye to a point one foot from that and so on, counting as he goes, "one, two, three and a half"—whatever he believes is right. Then have him take the foot rule and check his measurements accurately.
In the same manner the child should be taught to know and to be able to measure with the yard stick. With it, of course, measure larger objects, as the length of the house, the width of the porch, the distance from the house to the sidewalk, the width of the street, the height of the shed, etc. Teach the child to recognize the distance of a block, a half mile or a mile, and the size of an acre.
Unless you have had some practice in work of this kind, you will find yourself busy keeping ahead of the child. You can get excellent practice and development which will be of value to you, by entering into these exercises. Make it a point to become thoroughly interested in the work yourself, as it will insure continuation and increased good for the child. Remember the interest increasing value of competition.
While training the child's eye to measure, excellent practice will be found in determining comparative length of lines. The illustrations below will show some of the ways in which the lines can be made confusing. The child should be given enough drill in this exercise so that he learns to judge the things as they are, and not as they seem.
Have him look at Figure 1 and decide which is the longer line, a side of the square B or the diameter of the circle A. Then have him measure carefully.
In like manner compare the height of the two rectangles in Figure 2. Which line is longest in Figure 3—AB, CB, or BD? Which vertical lines are tallest in Figure 4—those between AB or BC?
In Figure 5 which line is longest, A, B or C?
Good practice can be had in judging the size of boxes by comparing the length of one box with the width of another, or any similar measurements. In each case the measurements should actually be made so that all error can be corrected.
In the same way practice with size and thickness of books. Let the child estimate them by inches so that he learns to determine accurately the difference in thickness. The carpenter can readily tell the full inch board from the seven-eights boards by looking at it or by feeling. His ability to do this is the result of practice.
The size of type is a good thing to practice with, as the irregular outlines of the type make it quite confusing. A sample book of type can be gotten from any printer. From this the child can also be taught to become familiar with the common type faces. This knowledge he can use to good advantage in later years.
The child should be taught a definite length of step for the purpose of measurement. In proportion to his size he can learn to step off two feet or a yard. He should also know the length in inches of his shoe for the purpose of checking shorter measurements.
Have the child know his height and estimate the height of trees, buildings, etc. These estimates can be checked by computing the proportion of the length of the shadow thrown by the tree and using the proportion.
Example—If the child is five feet tall and his shadow measures three feet, the shadow is three-fifths of his height. If the shadow of the tree measures fifteen feet, the height of the tree is twenty-five feet.
Further Development of Sight
There are two important faculties which are dependent upon the operation of the eye for usefulness and accuracy. They are Visualization and Perception. The games which are given later for the improvement of these important mental operations will also develop the sense of sight.
It will be better to use these later exercises where double results can be accomplished. Give all the time possible to the games on pages 59 to 69.