I did a search on the forum but did not come across references to effects of the eye on the autonomic nervous system as presented by Dr. Kaisu Viikari (she's an ophthalmologist). She also appears to have done pretty impressive work with regards to the development and prevention of myopia.
I apologise for the lenghty post, but I will try to summarize the essentials, as perhaps the information will be beneficial to interested people. (For the big picture, Dr. Viikari’s website is very well made and informative: _www.kaisuviikari.com)
So, it appears majority of humans are born hyperopic (hypermetropic), meaning that the eye is ”too short” as shown in the image:
For such an eye to see clearly in the distance, the accommodation muscle around the lens of the eye (ciliary muscle) has to contract to cause the lens to thicken, increase the refraction and lead to the images in the distance to focus on the retina:
It would appear that as such the eye is defective. However, the eye being too short enables seeing in the dark permitting hunting, etc., which was essential during paleolithic times. (If the person had an absolute normal refraction (emmetropia), he could not cope with the myopia provoked by darkness (so called ”night myopia”). The lens of the eye is incapable of reducing its refractive power from its original thickness.)
To see up close the hyperopic eye needs to accommodate even more (as seen in the below picture), and herein lies the problem.
In the olden times close work was minimal. In the modern world on the other hand reading, computers, etc. require an immense amount of close work demanding a lot of labor from the ciliary muscle. As any other muscle, the ciliary muscle can become spasmic and end up in a ”cramp”. In this situation the lens can remain in a thickened position, and the distance vision can be blurry. The situation is known as pseudomyopia, or school myopia:
If minus glasses are prescribed for a pseudomyopic eye with advice to read with them as well (as unfortunately is done routinely by the ophthalmologic profession), it locks the situation, and the accommodation spasm of the eye can’t release. With the person doing close work with these glasses, the situation actually deteriorates, the spasm worsens and the distance vision weakens. Often stronger minus glasses are prescribed.
Eventually the eyeball itself will lenghten, as the workings of the ciliary muscle cause the eye to grow axially (in a younger eye) causing anatomical myopia:
At the pseudomyopic phase, the situation could be reversed. This would require the use of glasses with plus additions when doing close work. In this way less accommodation is required from the ciliary muscle and it gets a chance to relax, with the distance vision improving:
If an axial, anatomical myopia has developed it is irreversible. However as there is an accommodation spasm present (that has driven the eye to lenghten), this portion of the total myopia can be reversed. The vision can improve to some degree (e.g. from -5 to -3.5) and worsening of the myopia is prevented. Also the possibility of many myopia related complications, like retinal detachment, is diminished.
For myopia and pseudomyopia prevention, Viikari suggests getting plus glasses (+3.0) for close work as early as possible.
All of the above shines a whole new light on refractive surgery, for example.
Everyone is individual, and some people of course do not produce (pseudo)myopia. I have understood that they might possibly be so hyperopic to start with, that the accommodation spasm worsening and the possible lenghtening of the eyeball do not cause things to go ”to the minus side”: the person’s distance vision doesn’t deteriorate. Thus they remain ”undiagnosed hyperopes” (latent hyperopia). The problem here is that as the accomodation process is linked with the autonomic nervous system, spasm of the ciliary muscle can potentially cause a plethora of problems from migraines to headaches, and more (of course this applies to the pseudomyopic situation as well). Writes Dr. Viikari:
and:
To alleviate these problems and release the spasm sufficiently a (latent) hyperope should have appropriate plus glasses for near, and far (as hypeopic eye has to accomodate to focus distant objects to the retina, as mentioned above).
A myopic person should try having weaker minus glasses for distance, and even weaker ones for close work. With both the myope and hyperope if/ when the accommodation spasm relieves and and the vision improves, new pairs of glasses will be necessary.
Viikari advices that especially older (over 35 yrs) people’s ”far” glasses should be bifocals (with age the lens of the eye becomes less flexible, with the accommodation muscle having to do more work, and near work becomes more difficult and tougher. Personal note: perhaps with the improved diet the flexibility of the lens could be maintained longer?). If looking from far to close, through ”full” monofocal minus glasses for example, one stresses the spasmic accommodation muscle with every glance. With the bifocal, the lower part has plus additions. An example:
Progressive multifocal lenses are pushed to people, as they have no discernible ”lines”, but according to Viikari:
There are variations to the bifocals:
Dr. Viikari is now retired, but in her time she really seemed to have to fight the establishment and received the usual harrassment reserved for someone trying introduce new paradigm-changing and people helping concepts (she successfully treated thousands of migraine patients). Corruption of science, indeed. A good review of Viikari’s experiences: _http://www.doyletics.com/arj/struggle.htm.
In my understanding, to this day these concepts are unfortunately not widely, if at all, acknowledged by ophthalmologists and opticians.
I apologise for the lenghty post, but I will try to summarize the essentials, as perhaps the information will be beneficial to interested people. (For the big picture, Dr. Viikari’s website is very well made and informative: _www.kaisuviikari.com)
So, it appears majority of humans are born hyperopic (hypermetropic), meaning that the eye is ”too short” as shown in the image:
For such an eye to see clearly in the distance, the accommodation muscle around the lens of the eye (ciliary muscle) has to contract to cause the lens to thicken, increase the refraction and lead to the images in the distance to focus on the retina:
It would appear that as such the eye is defective. However, the eye being too short enables seeing in the dark permitting hunting, etc., which was essential during paleolithic times. (If the person had an absolute normal refraction (emmetropia), he could not cope with the myopia provoked by darkness (so called ”night myopia”). The lens of the eye is incapable of reducing its refractive power from its original thickness.)
To see up close the hyperopic eye needs to accommodate even more (as seen in the below picture), and herein lies the problem.
In the olden times close work was minimal. In the modern world on the other hand reading, computers, etc. require an immense amount of close work demanding a lot of labor from the ciliary muscle. As any other muscle, the ciliary muscle can become spasmic and end up in a ”cramp”. In this situation the lens can remain in a thickened position, and the distance vision can be blurry. The situation is known as pseudomyopia, or school myopia:
If minus glasses are prescribed for a pseudomyopic eye with advice to read with them as well (as unfortunately is done routinely by the ophthalmologic profession), it locks the situation, and the accommodation spasm of the eye can’t release. With the person doing close work with these glasses, the situation actually deteriorates, the spasm worsens and the distance vision weakens. Often stronger minus glasses are prescribed.
Eventually the eyeball itself will lenghten, as the workings of the ciliary muscle cause the eye to grow axially (in a younger eye) causing anatomical myopia:
At the pseudomyopic phase, the situation could be reversed. This would require the use of glasses with plus additions when doing close work. In this way less accommodation is required from the ciliary muscle and it gets a chance to relax, with the distance vision improving:
If an axial, anatomical myopia has developed it is irreversible. However as there is an accommodation spasm present (that has driven the eye to lenghten), this portion of the total myopia can be reversed. The vision can improve to some degree (e.g. from -5 to -3.5) and worsening of the myopia is prevented. Also the possibility of many myopia related complications, like retinal detachment, is diminished.
For myopia and pseudomyopia prevention, Viikari suggests getting plus glasses (+3.0) for close work as early as possible.
All of the above shines a whole new light on refractive surgery, for example.
Everyone is individual, and some people of course do not produce (pseudo)myopia. I have understood that they might possibly be so hyperopic to start with, that the accommodation spasm worsening and the possible lenghtening of the eyeball do not cause things to go ”to the minus side”: the person’s distance vision doesn’t deteriorate. Thus they remain ”undiagnosed hyperopes” (latent hyperopia). The problem here is that as the accomodation process is linked with the autonomic nervous system, spasm of the ciliary muscle can potentially cause a plethora of problems from migraines to headaches, and more (of course this applies to the pseudomyopic situation as well). Writes Dr. Viikari:
and:
To alleviate these problems and release the spasm sufficiently a (latent) hyperope should have appropriate plus glasses for near, and far (as hypeopic eye has to accomodate to focus distant objects to the retina, as mentioned above).
A myopic person should try having weaker minus glasses for distance, and even weaker ones for close work. With both the myope and hyperope if/ when the accommodation spasm relieves and and the vision improves, new pairs of glasses will be necessary.
Viikari advices that especially older (over 35 yrs) people’s ”far” glasses should be bifocals (with age the lens of the eye becomes less flexible, with the accommodation muscle having to do more work, and near work becomes more difficult and tougher. Personal note: perhaps with the improved diet the flexibility of the lens could be maintained longer?). If looking from far to close, through ”full” monofocal minus glasses for example, one stresses the spasmic accommodation muscle with every glance. With the bifocal, the lower part has plus additions. An example:
Progressive multifocal lenses are pushed to people, as they have no discernible ”lines”, but according to Viikari:
There are variations to the bifocals:
Dr. Viikari is now retired, but in her time she really seemed to have to fight the establishment and received the usual harrassment reserved for someone trying introduce new paradigm-changing and people helping concepts (she successfully treated thousands of migraine patients). Corruption of science, indeed. A good review of Viikari’s experiences: _http://www.doyletics.com/arj/struggle.htm.
In my understanding, to this day these concepts are unfortunately not widely, if at all, acknowledged by ophthalmologists and opticians.
).
. This quite descriptive clip shows the accommodation muscle getting cramped, and leading to myopia (though it doesn't go into pseudomyopia more closely, etc.):
