William Horatio Bates

“ One of the best methods of improving the sight, therefore, is to imitate consciously the unconscious shifting of normal vision and to realize the apparent motion produced by such shifting. Whether one has imperfect or normal sight, conscious shifting and swinging are a great help and advantage to the eye; for not only may imperfect sight be improved in this way, but normal sight may be improved also. When the sight is imperfect, shifting, if done properly, rests the eye as much as palming, and always lessens or corrects the error of refraction. ”

“ When talking to people, one can shift from one person to another, or from one part of the face to another part. When reading a book, or newspaper, one can shift consciously from one word or letter to another, or from one part of a letter to another.
Shifting and swinging, as they give the patient something definite to do, are often more successful than other methods of obtaining relaxation, and in some cases remarkable results have been obtained simply by demonstrating to the patient that staring lowers the vision and shifting improves it. ”

“ No matter how good the sight, it will begin to blur, or even disappear, very quickly, and sometimes the effort to hold it will produce pain. In the case of a few exceptional people a point may appear to be held for a considerable length of time; the subjects themselves may think that they are holding it; but this is only because the eye shifts unconsciously, the movements being so rapid that objects seem to be seen all alike simultaneously.
The shifting of the eye with normal vision is usually not conspicuous, but by direct examination with the ophthalmoscope it can always be demonstrated. ”

“ When the patient is capable of a short shift, on the contrary, the long shift lowers the vision. The swing is an evidence that the shifting is being done properly, and when it occurs the vision is always improved. It is possible to shift without improvement; but it is impossible to produce the illusion of a swing without improvement, and when this can be done with a long shift, the movement can gradually be shortened until the patient can shift from the top to the bottom of the smallest letter, on the Snellen test card or elsewhere, and maintain the swing. ”

“ The building, the city, the whole world, in fact, may appear to be swinging. When the patient becomes conscious of this universal swinging, he loses the memory of the object with which it started; but so long as he is able to maintain the movement in a direction contrary to the original movement of the eyes, or the movement imagined by the mind, relaxation is maintained. If the direction is changed, however, strain results. To imagine the universal swing with the eyes closed is easy, and some patients soon become able to do it with the eyes open. ”

“ Later the feeling of relaxation which accompanies the swing may be realized without consciousness of the latter; but the swing can always be produced when the patient thinks of it.
There is but one cause of failure to produce a swing, and that is strain. Some people try to make the letters swing by effort. Such efforts always fail. The eyes and mind do not swing the letters; they swing of themselves. The eye can shift voluntarily. This is a muscular act resulting from a motor impulse. But the swing comes of its own accord when the shifting is normal. ”

“ Usually the eye with imperfect vision is able to shift from one side of the card to the other, or from a point above the card to a point below it, and observe that in the first case the card appears to move from side to side, while in the second it appears to move up and down. ”

“ Hence, when the eye shifts normally no error of refraction is manifest. The more rapid the unconscious shifting of the eye, the better the vision; but if one tries to be conscious of a too rapid shift, a strain will be produced. ”

“ A line of small letters on the Snellen test card may be less than a foot long by a quarter of an inch in height; and if it requires seventy shifts to a fraction of a second to see it apparently all at once, it must require many thousands to see an area of the size of the screen of a moving picture, with all its detail of people, animals, houses, or trees, while to see sixteen such areas to a second, as is done in viewing moving pictures, must require a rapidity of shifting that can scarcely be realized. ”

“ If one looks at the top of a letter, the letter is below the line of vision, and, therefore, appears to move downward. If one looks at the bottom, the letter is above the line of vision and appears to move upward. If one looks to the left of the letter, it is to the right of the line of vision and appears to move to the right. If one looks to the right, it is to the left of the line of vision and appears to move to the left. ”

“ If one eye is examined with this instrument while the other is regarding a small area straight ahead, the eye being examined, which follows the movements of the other, is seen to move in various directions, from side to side, up and down in an orbit which is usually variable. ”