by Leo Anghart
Many people who have undergone microsurgery or laser treatment find that they have merely changed their near-sight glasses for a pair of reading glasses. A lot of the people who attend my Vision Training classes have had refractive surgery of one kind or another. They come because their vision is beginning to revert to where they were before the surgery. Remember, the fact is that you are still near-sighted even after you’ve had your surgery. The actual condition of your eye that meant you had near-sight is still the same. What has happened is that part of the cornea has been shaved off, thus altering the focus of the eye. In effect, the lenses have been actually carved onto your eyes. It is really just a step further than wearing contact lenses.
If you want to know what can happen after refractive surgery visit www.surgicaleyes.org. This website is well-balanced and informative, with lots of articles and personal stories about what can and does go wrong with refractive surgery. A wise ophthalmologist says that refractive surgery should be the last resort. In the same way we thought that breast implants were safe, we do not know what will happen 10 or 20 years after laser surgery. The FDA only approved the most popular procedure, LASIK, in 1998 (see www.fda.govLASIK).
Since there is so much hype and disinformation about laser treatment, I have compared excerpts from the FDA’s LASIK surgery checklist with Vision Training.
Description LASIK surgery Vision Training
Know what makes you a poor candidate
Career impact Some employers prohibit laser surgery N.A.
Cost Between €1,500 to €3,000 per eye Workshop costs €350
Medical condition Illness that slows or alters healing N.A.
Stable vision Your vision must be stable for one year N.A.
Pupil size If your pupils are larger than 5.5 mm at night then you will experience starbursts N.A.
Corneal thickness Surgery not possible N.A.
Dry eyes Laser treatment aggravates dry eyes N.A.
You may need more than one procedure to achieve the result you want N.A.
You may still need reading glasses N.A.
Results may not be long lasting Results tend to last
You may experience permanent loss of vision N.A.
You may not be able to drive at night The FDA estimates that 20 percent of people lose contrast sensitivity making it impossible to see in dim light, such as restaurants, movie theaters, etc. N.A
You may experience halos and starbursts Some people experience permanent double or triple vision effects N.A.
Do not expect to see clearly for a few days The final result may take months to materialize You experience steady progress
Some people experience ghost images as in poor TV reception N.A.
Expect some pain and discomfort Expect to use eye drops to numb the pain N.A.
Complications include irregular astigmatism If the flap is wrinkled as a result of poor surgical procedure N.A.
Corneal ectasia can develop Due to the unavoidable thinning of the corneal tissue, the cornea can bulge out due to the internal eye pressure N.A.
28. Your Vision Training Plan
Check your eyesight Place the enclosed eye-chart on a wall in good daylight. Measure out the 1, 2 and 3 meter points from the chart. Check your visual acuity from 3 meters with both eyes.
Visual acuity of both eyes What is the lowest line at which you can see and name the letters correctly? Note the 20/?? (printed on the right hand side of the eye-chart).
Visual acuity of left eye Cover your right eye with your right hand. What is the lowest line at which you can see well enough to name the letters? Note the 20/??.
Visual acuity of right eye Cover your left eye with your left hand. What is the lowest line you can see well enough to name the letters? Note the 20/??.
If you have more than -5 diopters of myopia then you need to do the string measurement described on page 124.
Far point left eye Measure the distance from the end of the string to the far point of the left eye in centimeters.
Far point right eye Measure the distance from the the end of the string to the far point of the right eye in centimeters.
Notice if there is a difference. If so then you need to work at educating both eyes to have the same far point.
Check for astigmatism Look at the astigmatic mirror on page 92 and take in the overall image. If you notice that any of the lines are thicker, or are spaced closer or further apart, then you have an astigmatism. Be sure to check at different distances and test each eye as well.
Check eye-co-ordination Use a string as described on page 151. You should see a phantom cross right through the paperclip at any distance within your visual range.
Astigmatism
• Do the Tibetan wheel exercise as described on page 94.
Near sight less than 2 diopters (you have clear vision out to 50 cm)
• Wear glasses only when absolutely necessary such as when driving.
• Work with the eye-chart as described on page 110.
• Practice the swinging exercises as described on pages 111 and 112.
• Make it a habit to search for the smallest possible object you can make out at the greatest distance.
• Do this exercise if you wish to practice with your contact lenses in.
Near sight between 2 and 3 diopters (your vision is somewhere between 37–50 cm)
• Don’t use your glasses for reading and use them only when necessary.
• Do the string exercise described on page 124 to move your far point out.
• Practice with the chart-shifting exercise described on page 114.
• Play with the domino exercise on page 116.
• When you get closer to 2 diopters start doing the eye-chart exercise on page 110.
Near sight more than 4 diopters (you have clear vision only up to 25 cm)
• Wear lenses that are 0.5 to 0.75 diopter lower than your prescription.
• Do the energy exercise described on page 121.
• Do the string exercise described on page 124.
Eye co-ordination
• Work with the string as described on page 124.
Hyperopia
• Relax the eyes by using palming or by alternating hot and cold compresses.
• Exercise your ability to look at very small things very close-up.
• Don’t wear plus lenses unless absolutely necessary.
• Read small print up-close and as often as possible.
Presbyopia
• Bring your near point of clear vision up to about 15 cm from both eyes.
• Reduce your prescription if necessary.
• Do the reading smaller and smaller print exercise on page 136.
• Practice the lazy reading exercise on page 141.
• Check your eye co-ordination with the circle exercise on page 142.
• Start reading without glasses in the morning when there is good daylight.
Amblyopia
• Do the string exercise with the lazy eye on page 124.
• Do the energy exercise described on page 121.
Strabismus
• Do the butterfly exercise on page 160.
• Do the long body swing on page 161.
• Do the mirror exercise on page 162.
Training your color perception
• Count colors as described on page 176.
• Match colors as described on page 177.
• Work with colors as described on page 177.
• Arrange colors as described on page 180.
The visually impaired
• Gaining light perception see page 182.
• Mapping across the senses see page 182.
• Gaining object recognition see page 183.
Appendix: The Science of Vision Training
The capacity to achieve substantial improvement in unaided visual acuity is well documented by, among others the American Optometric Association (1988). Early research was conducted by:
The science of astigmatism
Over the years a number of researchers have come up with various theories about what causes astigmatism. The eminent German scientist Helmholtz (1909) suggested that due to anatomical factors, the eye would be expected to have against-the-rule astigmatism, but this tendency is countered by eyelid pressure, which tends to cause with-the-rule astigmatism. Duke-Elder (1932) suggested that with-the-rule astigmatism was related to the fact that the vertical diameter is slightly larger than the horizontal diameter.
Duke-Elder (1970) suggested that lid pressure could cause or alter corneal astigmatism. Vihlen and Wilson (1983) found that both with-the-rule astigmatism and the elastic coefficient of the lid decline with age, but they found no evidence that corneal torridity was determined by lid tension. Wilson et al. (1982) showed that lifting the eyelids reduced the corneal curvature in the horizontal meridian. They concluded that lid pressure did indeed produce some with-the-rule astigmatism, but generally, lifting the eyelids had little effect on corneal curvature when astigmatism was between 1 diopter with-the-rule or 1 diopter against-the-rule.
Pressure exerted by the extraocular muscles
A number of authors, including Fairmaid (1959), Bannon (1971) and Millodot and Thibault (1985), have reported that convergence of the eyes is accompanied by a falling of the horizontal corneal meridian, bringing about a slight increase in with-the-rule astigmatism or a decrease in against-the-rule astigmatism. Bannon (1971) estimated that the decrease in power of the horizontal corneal meridian accompanying convergence is from 0.245 to 0.5 diopters in non-presbyopic eyes.
Hofsteller and Rife (1953) concluded that astigmatism was mostly an environmentally determined trait. Lyle (1965) said that no hereditary patterns were discernible for astigmatism under 2 diopters.
Rigid contact lenses
Rigid contact lenses not only neutralize a portion of corneal astigmatism but often, with the passage of time, cause the cornea to become more toroidal. For example, wearing a flatter than normal contact lens in an attempt to reduce myopia (also known as orthokeratology) produces variable effects on corneal toricity, often including increased with-the-rule astigmatism. The development of with-the-rule astigmatism associated with the wearing of rigid contact lenses has been reported by many authors including Grosvenor (1977). The amount of astigmatism induced by polymethylmethacrylate (PMMA) lenses is reported to be from 2.5 to 6 diopters.
Residual astigmatism
Residual (internal astigmatism) refers to that part of the total astigmatism not attributed to the cornea. Residual astigmatism is against-the-rule astigmatism for most people (Neumueller, 1953) found 87 percent of the people he tested had against-the-rule astigmatism. Researchers found residual astigmatism between 0.5 and 0.75 diopters (Carter, 1972).
Researchers have mainly been interested in describing the phenomena of astigmatism. Only a few have suggested that the extraocular muscles may be involved in creating the corneal distortion typical of this condition. The Vision Training approach assumes that the exterior eye muscles, primarily the rectus muscles, are involved in distorting the cornea. This is not such a big leap of the imagination, since it is well known that the wearing of hard contact lenses leads to astigmatism.
The science of myopia
Myopia is the eye condition that has been studied more than any other. Interestingly enough, glasses were discouraged during the first half of the 1800s for myopia (MacKenzie, 1830) and for hyperopia (Sichel, 1837).
Is the prevalence of myopia related to the level of education?
The conclusion of early investigators (Cohn, 1867; Dor, 1878; Florchutz, 1880; von Jaeger, 1861; Ware, 1813) was that children in more intensive educational environments exhibited a higher prevalence of myopia. This finding was corroborated in a study of native Melanesian children (Garner, 1988), which showed a significantly higher prevalence among those who were involved in intensive study than those who were not.
Bind (1950) found almost no myopia among Eskimo children. Skeller (1959) reported that myopia was exceptionally rare among all Eskimos. However, in 1969 Young et al., reported that virtually no myopia existed among parents and grandparents, while more than half of the children of school age were myopic.
The ever increasing academic requirements for children is reflected by Sato (1957), where the prevalence of myopia increased from 15 percent in 1914 to an incredible 45 percent in 1955, when records of middle school children in Japan were examined.
Rosner and Belkin (1987) conducted a nationwide survey in Israel noting the degree of myopia and intelligence scores among 157,748 males aged between 17 and 19 years. This represented a largely unselected study population since all Jewish males of this age undergo medical examinations to check their fitness for military service. They found that both “years of schooling” and “intelligence” weighted approximately equally in their positive correlation with myopia.
Is the prevalence of myopia increasing?
Scheerer (1928) and Betsch (1929) examined 25,000 adults over the age of 25 and found that 13.7 percent of them had myopia. Walton (1950) examined 1,000 people aged between 30 and 90 and found 17.7 percent had myopia. British statistics from 2001 indicate that 61 percent of the population had myopia. Unfortunately, myopia appears to be increasing at an alarming rate.
At this point scientists do not know why myopia develops. There are many theories attempting to explain this, ranging from genetic disposition to simple over-use of the eyes for near work.
Does excessive near work lead to myopia?
Gross and Zhai (1994) propose a hypothetical mechanism explaining the development of myopia. They suggest that an individual who does a great deal of close work and who has a larger than normal lag of accommodation, and therefore a degraded retinal image, will be prone to myopia. This is because the lag of accommodation/focusing places the image formed by the optical system behind the retina. As a result, the axial length increases, having the effect of placing the image clearly on the retina.
Continued near work could cause the axial length to increase. This process is hypothesized to operate in the same way as the normal emmetropizising mechanism. Some researchers refer to this as emmetropization at the near point.
Gwiazda et al. (1993) suggest that in an individual who has poor accommodation, the blurred images – not the accommodative effect – are the cause of myopia. Accommodative responses were measured for newly myopic and emmetropic (normal vision) children under three conditions. In the first situation, the stimulus to accommodate or focus was increased by moving the target closer (therefore simulating proximally induced accommodation); in the second condition the stimulus to accommodate was increased by the use of concave lenses; and in the third condition the stimulus to accommodation was decreased by the use of convex lenses. When convex lenses were used to decrease the stimulus to accommodation, there was essentially no difference in accommodative lag for the two groups of subjects.
When accommodation was stimulated by moving the target closer to the subject, the mean lag of accommodation was similar for the myopes and emmetropes at all but the closest distance of 25 cm, where the lag for the myopes was 0.4 diopters greater than for the emmetropes. However, when concave lenses were used to increase the stimulus to accommodation, the lag of accommodation was significantly greater for the myopes. A -3.50 diopter lens (the highest power used) read approximately 2.7 diopters for the myopes as compared to 1.5 diopters for the emmetropes.
Gwiazda et al., suggest that “reduced accommodation is found for a period after, and perhaps before, the onset of myopia, at whatever age it occurs” (1993: 693).
Experimentally induced myopia
The environment has a great influence on vision. For example, laboratory monkeys are f
ound to be considerably more myopic than wild monkeys, and monkeys kept indoors in cages develop more myopia than animals kept in outdoor pens (Young, 1967).
The German researcher Levinson was the first person to conduct animal experimentation. Levinson believed that myopia resulted from the pull of the optic nerve when the eyes are held in a downward position, so that the anterior–posterior axis of the globe is oriented vertically. To test the theory, monkeys were placed in a box that was parallel to the floor, with the result that after a few months, myopia was found to occur and increased as long as the experiments were carried on. Griswell and Gross (1983) kept three monkeys in this position. One of them developed 14 to 15 diopters of myopia after nine months, the second developed 7 to 9 diopters of myopia after one year, and the third developed 1 to 2 diopters of myopia after four weeks. Intraocular pressure did not increase during the experiment and the myopia was axial in nature; in other words, the eyeball elongated in a way that is typical of myopia.
