by Leo Anghart
The conventional explanation is that the fault is inherent in the eyeball – either in the cornea or the entire eyeball – which is presumed to be congenitally distorted. Ophthalmologists generally define astigmatism as caused by the toroidal anterior corneal surface.
In other words, astigmatism is an irregularity in the curvature of the cornea caused by tension and pressure on the eyeball. In rare instances, astigmatism can form in the lens or in the retina.
Optically, astigmatism is corrected by the combination of spherical and cylindrical lens elements that form a complex curved shape, somewhat like the sections of a football. To make this work the optometrist needs to define the axis of the refractive error – two lines at right angles to each other – which indicate the greatest and least degrees of the error. He must also ensure that the lens is worn in exactly the right position.
Contrary to traditional belief, astigmatism is very fluid and is usually easy to correct – relaxation is the key.
Astigmatism is one of the vision problems that responds beautifully to Vision Training. I have seen mild astigmatism (less than 1 diopter) vanish after just a few exercises. Some time ago I gave an introductory talk at a conference held at Regent’s College in London. In the audience there was a woman who remarked that some of the lines on the eye-chart seemed to be darker than others (this is a sign of astigmatism – see the astigmatic mirror on page 92).
After guiding the group through the Tibetan wheel exercise (see below) I showed the woman the astigmatic mirror once again. She cried out, “It’s the same, it’s the same.” Everybody assumed that she was talking about the astigmatism; in fact she was talking about the lines on the astigmatic mirror. Suddenly everyone realized that the astigmatism had gone after just one exercise. Astigmatism does not always go that fast. However, most people will notice that a change has taken place.
In most cases astigmatism will disappear after exercising for just a few days. With more severe cases it may be necessary to do the Tibetan wheel exercise for a few weeks before the eyes return to normal.
Vision Training principles for astigmatism
• Exercise the exterior eye muscles at a gradual pace, so they become more flexible.
• Get feedback in the form of an astigmatism chart. It is important that you know how you are progressing.
There is growing evidence that the development of astigmatism is formed by environmental influences as well as the personal visual habits that you have adopted. The rigidity of the cornea, which may vary individually from person to person, also plays a role. The flexible corneal tissue reflects the stress patterns influencing the eye. This is similar to putting up a tent. If you don’t maintain equal tension in the wires your tent will tilt in the direction of the wire you have tightened the most.
In Vision Training we adopt the presupposition that astigmatism is mainly caused by tension carried in the rectus muscles located around the eye. Consequently, the best strategies for correcting astigmatism involve exercises designed to loosen or adjust the tension held in those muscles. Many of the body’s muscles are kept on a continuum between being totally relaxed to very tense. Your neck muscles are a good example of this – you have probably experienced having really tense neck muscles at some point in your life. During the day you maintain a delicate balance between tension and relaxation in order to keep your head movements flexible. You are ready to move in any direction the very instant your attention is drawn to something in your environment.
Astigmatism can develop when the upper and lower rectus muscles (the four muscles that control the eye’s movements from left to right and up and down) are too tense. This results in an excessive up and down pull which causes the cornea to curve more along the vertical meridian (the 12 o’clock–6 o’clock line). It flattens slightly along the sides, producing typical with-the-rule astigmatism. Since astigmatism is caused by tension in the muscles around the eyes, the best way to correct it is to release the excess tension. In the following exercise we will explore a couple of ways you can quickly identify which of your muscles are tense, and then begin to relax them.
First, look at the astigmatic mirror or the circles above and identify your current state. Try looking at the chart from several distances. For some people there is astigmatism at certain distances only. Find out if your astigmatism is more pronounced close to or far away. If so, this will be valuable information later on when you want to check your progress.
Note that the astigmatic mirror will only be accurate within the field of your clear vision. Outside the range of your natural vision the chart is not reliable. However, as your vision continues to improve, the chart will stay accurate. As you exercise, check the astigmatic mirror from time to time to monitor your progress. You will notice that the darker lines begin to even out or the lines will begin to appear to be of the same length all around.
Exercise to loosen the eye muscles
This exercise is designed to gently loosen the muscles of your eyes before attempting more strenuous exercises. The objective is to induce flexibility in the muscles. If you find this exercise is painful then go slowly. Don’t attempt the Tibetan wheel exercise before you can do this exercise very comfortably.
1. Place your thumbnail straight ahead in front of your eyes. Your thumb should be less than the width of your hand from your face. Some may not see the thumbnail clearly. This is all right since we only want to exercise the muscles.
2. Now, very slowly, move your thumbnail straight up. Keep your head still and follow the thumb up as far as you can see. Then, very slowly, move your thumb straight down. Continue to move your thumbnail to the various angles shown on the drawing.
3. When you have done one round of this, relax your arm and eyes for a moment. When you are ready, do the same exercise again, but this time synchronize your movements with your breathing. As you are moving your thumb up, inhale, and as you are moving your finger down towards the center exhale as slowly as you possibly can. Notice how your entire body begins to relax, including your eyes.
4. Do this exercise with synchronized breathing once in a clockwise direction and once in a counter-clockwise direction.
Did you find that moving towards some of the angles was more difficult than others? This is an indication that your rectus muscles are less flexible at those angles. Check your progress on the astigmatism chart on page 92.
Do this exercise three times a day with a few hours of rest in between. It is a kind of aerobics for the eyes. You want to just touch the tension and then relax. Doing this repeatedly over a period of time will loosen up and greatly reduce any tension you have in your eye muscles and, as a result, your corneas will begin to revert to their natural shape.
Tibetan wheel exercise
This exercise will stretch your eye muscles much more due to the sharp angle between the Tibetan wheel chart and your eyes. By moving your eyes in various steep angles around the dial you begin to stretch your eye muscles and as a result they begin to recover their normal flexibility and your corneas will revert to their original shape, thus restoring clear natural vision.
How to move your eyes
1. Place the Tibetan eye-chart about 2.5 cm from your nose with the tip of your nose at the white circle in the center. You may not be able to see the chart sharply; the purpose is to exercise your eye muscles.
2. As you inhale let your eyes jump up from step to step until you can see the ball. Then let your eyes jump down the steps at the same rate as you exhale, as slowly as possible. Let your entire body relax.
3. Let your eyes follow the smooth spikes. Inhale as you go out and slowly exhale as you come back towards the center.
4. Continue around the chart, first in a clockwise direction, then in a counter-clockwise direction.
5. Do this exercise three times a day with a few hours of rest in between. Check your progress by looking at the astigmatism chart on page 92.
Some people like to play slow relaxing music as they do this exercise. The rhy
thm of the music will enhance the calming effect. As mentioned earlier, astigmatism is normally quite easy to eliminate through the exercises outlined above. In many cases just a few days of regular exercise is enough to restore normal clear eyesight. You will know you have achieved this when you can move your eyes easily in all directions and see the astigmatism chart on page 92 clearly without distortion. Remember to look at the chart from several distances and particularly where you noticed any distortion prior to your exercise program.
The size of this chart is important please download it from www.vision-training.com/en/Download/Download.html
The exercises are safe as long as you do not over-exert your eye muscles. Take it easy and allow your muscles to regain their natural flexibility over a few days or weeks. What’s worth doing is worth doing well. Should your astigmatism return you now know what to do.
Exercise without the chart
If you have astigmatism in one eye or the axis of the astigmatism is different in each eye, you can do this exercise to release the specific muscle group that holds the tension.
By now you have ascertained at what angle your muscles are most tense. For example, you may have found that the tension lies along the 2 o’clock–7 o’clock axis.
1. Hold a finger or a pen about 3 cm from your eyes and move it back and forth along the axis three times. Each time go as far as the eyes will go.
2. Now, close your eyes and imagine yourself doing the same thing, except that you are moving the eyes further in each direction. Imagine yourself doing this three times.
3. Next, do the exercise again with your eyes open. You will notice that you can move your eye a bit further.
4. Finally, do the exercise for the opposite axis as well (the 11 o’clock–5 o’clock axis). This is done to ensure that you are not just shifting the astigmatism from one axis to another.
Some objective proof
Astigmatism is identified on topographical images of the eye as a “bowtie” pattern (see the following picture). A topographical image can be compared to the lines on a map which show the contours of a landscape. The images you see on this page are taken one day apart and offer very impressive evidence of how effective eye exercises are for astigmatism.
The image on the left shows half a diopter of astigmatism (C: -0.5). Note the typical bowtie pattern which indicates the axis of astigmatism, in this case 83° (A: 83).
The image on the right shows the same eye the next day after Vision Training exercises. You can see that the red color has spread, indicating that the eyes have returned to normal and no longer measure any astigmatism. The eyes have also regained +0.25 diopter of hyperopia. This is objective proof that Vision Training is effective for astigmatism.
13. Myopia
Near-sight or myopia is the most common vision problem and will touch the lives of almost half the population at some time or another.
When you experience the first signs of myopia, you can still see what’s going on in your immediate environment quite clearly. It is only objects in the distance that appear blurred. Myopia usually starts during the school years when you begin to realize that you have trouble seeing what is written on the board. At first it is easy to cope with but it soon becomes more of a problem. You get your eyes tested and then usually get fitted with glasses. However, as soon as you begin to wear glasses you find that the myopia only tends to progress and worsen. You will then need a stronger prescription in order to see comfortably. Soon you find that you are wearing the glasses the whole time, when the truth is that you could see perfectly well without them.
What causes myopia?
The loss of distance vision has been acknowledged since ancient times. The Greek concept of myopia was that too little “spirit of vision” poured out of the brain and hence the vision was too feeble to extend to a distant object. However, not much attention was paid to vision problems until the mid-nineteenth century. Interestingly enough, during the first half of the century the use of glasses was discouraged. They were thought to aggravate the existing problem and be harmful.
During the 1860s, German ophthalmologist Herman Chon observed that myopia increased as children progressed through school. In 1867 Dr. Chon published a study of the eyes of 10,000 children attending the schools of Breslau. He arrived at what seemed a reasonable conclusion: namely, that use (and, in particular, abuse) of the eyes was what caused myopia. Chon’s theory dominated for the next 50 years and a crusade began for better standards of visual hygiene in schools throughout Germany.
The Dutch ophthalmologist Franciscus Cornelius Donders believed that myopia occurred as a result of prolonged tension on the eyes during close work and the elongation of the eyeball. In On the Anomalies of Accommodation and Refraction of the Eye, he writes:
How then is this prolongation explained? There are three factors to be taken into consideration: 1) Pressure of the muscles on the eyeball in strong convergence of the visual axes; 2) Increased pressure of the fluids, resulting from the accommodation of blood in the eyes in the stopping position; 3) Congestive processes in the fondus oculi, leading to softening, even in the normal eye, but still more under the increased pressure of the fluids of the eye, giving rise to extension of the membranes. This increased pressure causes the extension to occur principally at the posterior pole, and is explained by the want of support from the muscles of the eye at that part. (1864: 343)
Accommodation
Accommodation is a theory first suggested by German scientist Hermann von Helmholtz in 1863. It refers to the refractive state of the eye due to change in the curvature of the lens in order to focus a sharp image on the retina.
When the ciliary muscle, which is located around the lens, contracts, the tension decreases to allow the lens to bulge out and become thicker. The thicker lens is said to have accommodated. The right-hand image (A) shows the lens accommodated.
On the other hand when the ciliary muscle relaxes, the lens is pulled out and it becomes thinner. This is referred to as the un-accommodated state.
Accommodative amplitude refers to the distance from the eye to the point of the first slight sustained blur or far point, converted into diopters. This is the clinical amplitude.
Until the invention of equipment that could accurately measure the size of the eyeballs in a living human being, it was believed that the ciliary muscle got weaker and could no longer focus the lens. This theory is still offered as the explanation for myopia by many eye-care professionals. Ultrasound scans have shown objectively that with a high degree of myopia there is an elongation of the eyeball. What causes that elongation is a matter of opinion. Some researchers thought that the problem was increased pressure in the eye. For example Kelly et al. (1975) refer to myopia as “juvenile expansive glaucoma.” However, the pressure theory is unlikely, since both coughing and an increase in body temperature cause an increase in intraocular pressure.
When vision blurs
When the optic elements of the eye focus the image on the retina you have sharp vision. If the image is out of focus the image on the retina will form blur circles.
Just as in the case of the aperture in a camera, the depth of field varies in the eye according to the diameter of the pupil. The relative size of the blur circle increases in proportion to the distance of the optical image from the retina. In myopia, the optical image is located in front of the retina and consequently you perceive an out-of-focus image.
Blur circles differ according to the shape of the object in view. For example, a line will look like a series of small blur circles (object points) one above the other. On the other hand, a two-dimensional image, such as an eye-chart, is formed by lots of blur circles following the shape of the letter you are looking at.
Pinhole glasses take advantage of this phenomenon. The many tiny holes decrease the blur circles with the result that you perceive a clearer image. Pinhole glasses generally give you an idea of what your vision would be like if fully corrected.
In a study published in
1969, Coleman et al. demonstrated changes in the axial length of the eye with accommodation. Young (1801) and Bell (1827) both suggest that increased vitreous pressure, resulting from sustained accommodation during prolonged near vision, plays an important role in axial elongation and the development of myopia. This seems to correlate with the experience of computer users and others involved in near work.
Peter Greene (1980) evaluated the stress experienced on the eyes based on engineering principles. He examined the stress forces on the sclera by accommodation, convergence, vitreous pressure and the external eye muscles. Greene concluded that the mechanical effects of convergence completely dominate those created by accommodation, even though both occur simultaneously when the eyes focus on a very close target. His calculations show that the total stress experienced by the posterior sclera is the sum of the stress induced by intraocular pressure and by the oblique muscles. He found that the region between the two oblique muscle attachments is subject to a tensile strength higher than those at any other location of the eyeball. This theory, therefore, could account for the axial lengthening of the eyeball that occurs in high myopia.
New York ophthalmologist William H. Bates (1915, 1918), after four years of research into the accommodation and focusing of the eye, came to the conclusion that the oblique muscles are the major factor in the focusing of the eyes. He believed that the ciliary muscle and the lens were only of minor importance.