Whatever the truth about the mechanism of accommodation, there can be little doubt that it is based on muscular movement or something very much like it. Regular use and exercise of muscle systems elsewhere in the body always lead towards health and normality of function, and there is no reason to suppose that the same is not true of the muscle systems of the eye.
Let us once again go back to first principles, and consider the way the human species has evolved. Until a very recent time, in evolutionary terms, that is, the human animal made its shelters of brushwood and skins, or took refuge in those rather rare but secure natural shelters, caves. Because artificial lighting was so primitive as to be almost useless, the shelters were occupied mainly for sleeping or during bad weather. For the rest of the time, our ancestors spent their lives outdoors, whether hunting, fishing, gathering food plants, making or repairing clothes or utensils, or just sitting round the camp fire doing nothing. They spent their lives outdoors, because there were no such things as doors.
The point is that the human eye evolved in conditions very different from those that prevail today. The universal use of electric lighting, and the simple fact that we now live in buildings, have together deprived the eye of distance and severely limited the range over which most of its accommodation is done. It is noteworthy that glasses are unusual among those people — agricultural workers, for example — whose way of life demands that they spend much of their time under the sky.
Once any muscle is deprived of its full and normal range of use, it begins to atrophy. So with the mechanism of accommodation. Lack of distance — together with the emotional causes discussed in previous chapters — is one of the factors contributing to its deterioration. If the other causes are overcome, if glasses are not worn, and if the eye is again supplied with the full range of distance it needs, focusing ability will gradually be restored.
What this means in practical terms is that you should endeavour to get out and about at least once a day; and, when you are out, let your eye range constantly from far to near. This will help you whether you are long-sighted or short-sighted, but short-sighted people will find it of special benefit. Make the most of bright, sunny days, because then the pupil contracts, the depth of focus is increased, and refractive error is reduced to its minimum, so that the eye is more likely to be coaxed into better habits of accommodation. For developing better eyesight, walking is the way to travel, as then you have time to appreciate the view as well as the depth of field as made manifest by passing objects. Do not waste any opportunities for distance vision afforded by trips by road or rail, although looking through glass is never as satisfactory as being in the open air.
You can encourage the recovery of focusing ability by allowing the eye to follow approaching or departing vehicles. Car numberplates or the lettering on vans and lorries may be used as convenient “test charts”, and any journey by road can be transformed into a session of accommodation practice. Even better than this is to stand on a bridge over a motorway; if you are long-sighted, concentrate on watching the traffic as it approaches and passes below you; if you are short-sighted, allow the receding vehicles to draw your gaze ever further into the distance. Watch one vehicle at a time, and memorise brief episodes from this practice for use later in your palming and visualisation sessions. It does not matter if your focusing ability does not keep pace with your attention. One of the causes of difficulty in accommodation is a subconscious reluctance to look into the distance or close to, and the mere fact that you are deliberately challenging this reluctance is enough to bring about an improvement in attitude and hence, ultimately, in accommodation itself.
When indoors you should remain aware of the need for frequent changes of focus. While reading, look up from the page at regular intervals — say at the end of each long paragraph or each page — and, just for a second, consciously focus on some distant object. While watching television, keep a light on in the room and frequently look away from the screen, whether at an object nearer or farther away.
If you are already able to focus at reading distance, get into the habit of, now and then when you are alone, examining very closely some small object. Insects — if you can bring yourself to look at them — make a fascinating subject for study with the naked eye, as do leaves, flowers, bits of bark, ferns, feathers, pebbles: in fact, anything from nature. Examine also the minute appearance and texture of such objects as your front door key, pen nib, or wristwatch. Use both eyes together, and from time to time measure and make a, note of the minimum distance at which you are able to focus.
Besides these suggestions for accommodation practice in day to day life, the Bates method provides certain specific drills, each of which is a variation on the same theme of exercising the mechanism of accommodation.
This is perhaps the simplest of the accommodation drills. Cut a strip of paper about eight centimetres (three inches) long and two centimetres (slightly under an inch) wide, and in the centre mark a small ink cross. Wrap the strip of paper round the base of the middle finger of your left hand, in such a way that the cross is towards you when the palm is uppermost. The strip is held in place by your ring and index fingers.
Cover your right eye with your right hand and, watching the cross, bring it slowly closer, and closer still, beyond your nearpoint, until it is merely a blur, and then make it slowly retreat. Take it out to arm’s length and bring it back rather more quickly. Do this five times in all, accelerating as you go, so that at the end your hand is moving fairly rapidly.
Repeat with the right hand and the right eye, and then, still with the strip on your right hand, with both eyes together. Pause, look into the distance, and repeat the whole drill once more. Slowly build up to five repetitions, making six sets in all. Zooming can be relatively strenuous in the beginning, so do not try to attempt too much, and stop immediately if you find yourself becoming tired or losing interest. Should you not have a bit of paper by you, close your hand slightly so that one of the creases in your palm becomes more pronounced, and use that as your object instead.
The basic test chart (Chart A) comes with two reductions of itself at one quarter and one eighth scale (Charts B and C). Depending on the nature of your refractive error and the state of your eyesight, you should be able to read part of at least two of the charts when the larger is at the distance and the smaller is near at hand. By “the distance” is meant any distance in excess of 3 metres (10 feet) and, for practical purposes, under about 6 metres (20 feet). If you are very myopic or your sight is otherwise bad, “the distance” may be taken to mean the greatest range at which you can read the first two or three lines of Chart A. For some, that may be as near as a couple of metres (5 to 6 feet). As your Bates training proceeds, you should be able to increase this fairly steadily until you can read two or more lines of Chart A at 3 metres (10 feet).
Fix Chart A to the wall at eye level. You may find it convenient to paste the chart to a sheet of hardboard or stout card and arrange a loop of string at the back, picture-fashion, so that it can be taken down when not required. Make sure the chart is in a good light. Strong daylight is best. The standard specification for opticians’ test charts recommends two ordinary 60 watt lamps mounted about 35 centimetres (15 inches) from the chart and inclined towards it at an angle of about 15 degrees, or a single 100 watt spotlight reflector (of the type mentioned in the chapter on sunning) about 1.5 metres (5 feet) away. This level of illumination is adequate for testing, but for visual re-education a considerably brighter light is better. If the 100 watt spotlight is brought to within 50 centimetres (20 inches) of the chart or less, the pupil of the eye contracts and depth of focus is improved. This level is recommended for all practice work with the chart, number board, dominoes, and any other material at the distance.
Now, seated at a table or in a comfortable chair, prop or hold one of the smaller charts in front of you, in such a way that you can glance easily from one chart to the other. If you can read Chart C, use that; otherwise use Chart B. In either case the apparent size of the small chart should be about the same as that of Chart A. The small chart, like Chart A, should be strongly illuminated, preferably to a similar level, so that the two charts resemble each other in all respects but their distance from your eyes.
Palm for a while, and then look at the chart which you see more clearly. Starting with the big C, and continuing with each letter in turn, find the letter first on this chart and then on the other one. Notice that the letters are identical in everything but distance. The letters are inert, waiting to be seen. They are made of printers’ ink, one of the blackest substances known. The reason that you see the letters of one chart grey and the other black has nothing to do with the letters themselves. The illusion lies entirely in your own perception. The grey letters are every bit as black as the others. As you look at them, acknowledge this self-evident fact to yourself, and, without reference to what you are actually seeing, imagine that they appear just as black as the letters on the easier chart. Try also the same visualisation technique as you used with the number board, assigning to the imperfectly seen letter the blackness and clarity of the other.
Read as much as you can (without strain) of the easy chart, palm once more, and repeat the whole process. If you are able to read part or all of Chart C at reading distance, vary the procedure on occasion by having all three charts in view and looking from one to another in ascending or descending order of size.
The test charts, singly or together, may be used in other ways also. The letters serve as excellent subjects for visualisation, swinging, and shifting. Practise shifting from top to bottom and side to side of individual letters, first on the easier chart and then on the harder one. Shift also between similar letters of different sizes on the same chart. Then shift between corresponding pairs of letters on the other chart. As you transfer your glance from far to near, do so easily and unconcernedly. Remember always that good vision cannot be achieved through effort or strain.
As a supplement to the charts, an astigmatism indicator is provided in Appendix B. According to the nature of your astigmatism, if you have any, at least one of the arms of the indicator will appear more blurred than the others.
The charts and the indicator are invaluable in reinforcing the feedback from brain to eye. This feedback is the key to recovering focusing ability. If the image improves, however fleetingly, the brain needs to be informed and, as it were, congratulated. It must be encouraged to repeat whatever it did that produced the improvement. The letters on a test chart, unlike most ordinary objects, give a very precise indication of how well the eyes are working. Looking at a chart between spells of palming will alert you to any changes, no matter how subtle, that are taking place in your vision. At first these changes will be so slight that you will probably dismiss them as imaginary — until, perhaps, you recall that imagination and vision are very much of the same. Later the changes will become more marked and dramatic, and you will almost certainly be surprised to find how much your eyesight varies from moment to moment and from day to day.