Angart Magic Eyes

Vision training for children
1. Auflage 2015
ISBN: 978-1-84590-965-9
Verlag: Crown House Publishing
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 224 Seiten

Leo Angart runs workshops all over the world, helping people to regain their natural vision and throw away their glasses for good. He regularly encounters children whose eyesight is being adversely affected by their glasses or who don't really need glasses at all. In Magic Eyes: Vision Training for Children Leo shares his experience and explains what you can do to help transform your child's eyesight, eliminating the need for glasses. In Magic Eyes Leo Angart demystifies common eye conditions, explains the causes of these issues and suggests simple solutions you can try at home. These fun exercises can make children's eyes healthy and strong and eliminate the need for glasses. In fact with children it is actually quite easy to restore natural eyesight within a week or two. Magic Eyes also contains detailed explanations of, and exercises for: amblyopia (or lazy eye), anisometropia (when vision is different between the left and right eye), astigmatism (irregular shaping of the cornea), diplopia (double vision), hyperopia (far-sightedness), myopia (near-sightedness) and strabismus (turning in or out of the eye).

Leo Angart is a business consultant, author and trainer. Having worn glasses for more than 25 years he speaks from personal experience. It has now been more than 19 years since he threw away his glasses.

Autoren/Hrsg.

Angart, Leo

Leseproben

7. Focusing Efficiency

At birth focusing is poorly developed. A newborn is able to focus to about 30 cm from their eyes – just enough to see mom or dad’s face. During the first three months, depth of focus decreases and the focusing response improves. The primary trigger for focusing to activate is blur: the things you want to see are unclear so the focusing mechanism is activated. Through the first six months there is a rapid development, so the focusing ability is fully developed in a 6-month-old baby.

Behavioral optometrists believe that children with reading difficulties have a high rate of focusing disorders due to accommodative infacility. Hoffman (1986) examined 107 learning disabled children in whom he found very high degrees of binocular or eye co-ordination problems (87%). Accommodative or focusing problems were found in 83% of the children. Hoffman also found that almost all of them (95%) had ocular mobility or eye movement issues which interfered with their ability to read. There appears to be ample evidence for the behavioral optometrist’s claim.

Children must be able to sustain the average eye-to-desk distance of 30 cm (3 diopter focusing or accommodative demand) for 30–45 minutes or longer. If they are lacking in sufficient visual power or stamina, the child will develop visual fatigue or will resort to avoidance behaviors. This will be particularly true for far-sighted children, since they need to use more power to focus their eyes on the book. Without the required visual stamina to focus for the duration they simply get tired.

Modern ergonomically designed school desks are adjustable so the proper reading distances can be altered with the natural growth of the child. These desks also have a book rest that is further away than is traditional – a recognition that many first graders are far-sighted. It would also be helpful if books could be printed with larger lettering, so that it is easier for the child to read without straining their focusing system.

Behavioral cues to look out for, especially after a long period of reading or near work, include:

Reports blurry vision at near tasks.

Reports blurry vision at a distance after near work.

Reports eye fatigue after short periods of reading or writing.

Holds book too close.

Has difficulty sustaining near tasks.

Rubs eyes excessively.

Reports feeling a pulling sensation around the eyes.

Has red eyes.

Is tired and sleepy.

Avoids near-vision tasks like reading.

If you observe any of these symptoms, especially blurry distance vision after reading, then it is advisable to investigate further.

There are three main focusing problems. These have different causes but very similar effects.

1. Accommodative insufficiency

If a child has accommodative insufficiency then the amount of focusing ability available (the amplitude of accommodation) is less than what is expected for their age. The child will experience intermittent blurred vision when reading. In an attempt to obtain clear vision, they will try harder and this may lead to some of the symptoms listed above.

2. Accommodative excess

Accommodative excess occurs when the child is overdoing reading or playing video games. They will have blurred vision when looking away from the book or games device. This may also lead to myopia. Initially this myopia is referred to as pseudomyopia (temporary myopia) or, putting it simply, tired eyes. If the activity is continued it becomes real myopia and the child is fitted with minus glasses. In Asia, pseudomyopia is the leading cause of myopia and increasingly so in other parts of the world as more children spend hours every day on computers or video games. It is interesting to note that pseudomyopia can also be induced by wearing the wrong glasses.

3. Accommodative infacility

This is a condition in which the amplitude of accommodation, or visual power, is normal but the speed of the response is reduced. The most common complaint with accommodative infacility is blurred vision when looking from near to far and back again. The child will find that it takes a while before their vision is clear.

Testing focusing efficiency

Most optometrists and eye doctors only test the amplitude of accommodation. However, only presbyopia and accommodative insufficiency can be detected using this method. The child should also be tested for accommodative facility. This tests their ability to change focus rapidly near and far for a sustained period of time. It is the only suitable method for detecting accommodative infacility. Obviously, this is a key test because it will reveal the actual problem the child is experiencing.

The optometrist may test for both negative relative accommodation (NRA) and positive relative accommodation (PRA). NRA is a measure of the maximum ability to relax accommodation with clear vision, and PRA measures the maximum ability to accommodate.

The test is as follows: after the distance correction is established, the child is instructed to look at small letters at reading distance. The optometrist now adds lenses in -0.25 diopter increments until they report that the text has become blurry. The total value of the minus lenses added is the positive relative accommodation. Values over -3.50 diopters will indicate accommodative excess, or over-worked eyes. Children with accommodative insufficiency typically have values less than -1.50 diopters.

The standard method for testing accommodative facility is a lens rocking procedure using a pair of +2 diopter lenses on one side of a flipper and -2 diopters on the other side. The test is done at normal reading distance. The child starts off by trying to read through the -2 diopter lens. When they report that the text has become clear, the lenses are flipped to +2 diopters. Again, when the child reports that the text is clear, the lens is flipped again. This flipping is done for one minute. The optometrist counts the number of cycles (changes). Assuming there are no eye co-ordination issues, the child should be able to do eight cycles per minute using both eyes.

Another important way of evaluating the child’s focusing ability is near-point retinoscopy. This is particularly useful in detecting accommodative excess. A dynamic retinoscopy technique called monocular estimate method (MEM) is a reliable measure of accommodative accuracy (i.e. lag and response). MEM is carried out under normal reading conditions, including reading distance, angle of view, posture and lighting. In other words, the actual environment in which the child is reading is approximated for the test. This is because it is important to rule out all possible factors that might influence the accuracy of the test.

For the test, the child is asked to read words on a card that is attached to the retinoscope. The optometrist interposes plus lenses with varying power in-between the retinoscope and the eye until the lag of accommodation is neutralized. The lens is interposed only briefly, so there is minimal interference with the natural focusing response.

The normal range of accommodative lag expected for children aged between 5 and 12 years is from plano (no power) to +0.75 diopters. If the lag is more than +0.75 diopters the child may be far-sighted. Of course, the influence of prescription medications and so on must be ruled out. A 10-year-old has a maximum of about 12.50 diopters of accommodative amplitude. Falling 2 diopters below this is usually associated with symptoms such as far-sightedness. Hofstetter’s formula for predicting the minimum range of accommodative amplitude at different ages is:

D = 15 – one quarter of the child’s age

So, for a 9-year-old, the minimum expected amplitude is 12.75 diopters (15 – 2.25).

Testing amplitude of accommodation

Reliable evaluation of a child’s accommodative facility can be carried out from the age of 7. To test the focusing power of your child’s eyes, you need a tape measure and a small card printed with text at a 14 point font size, like this:

CAPITAL LETTERS ARE EASIER.

To perform the test, follow these instructions:

1. Ask the child to cover one eye.
2. Hold the card about 3 cm from the eye and slowly move it out until the child says the text is clear.
3. Measure the distance from the eye to the near point of clear focus.
4. To get the amplitude of accommodation divide 100 by the measurement you have taken. (e.g. if the near point is 8 cm then the amplitude of accommodation is 100 divided by 8 = 12.50)
5. Compare the amplitude with what is expected at that age (use Hofstetter’s formula above). The minimum expected amplitude is 15 diopters minus a quarter of the child’s age. If the amplitude of accommodation works out to more than 2 diopters less than what is expected, further tests will be necessary.

Years of age

Diopters

7

13.25

8

13.00

9

12.75

10

12.50

11

12.25

12

12.00

Amplitude of...