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I would like to know whether my job environment may jeopardize my sight recovery, doing the exercises



FAQ n. 35. Power Vision System - 
I work as a dental technician and I would like to know whether my job environment may jeopardize my sight recovery, doing the exercises.



- Answers David De Angelis

The answer is Yes. One’s job environment as well as the life one leads acts on our refractive state, since we get used to our visual environment. Constant near-work can make focusing at a near distance (the process of accommodation) “become chronic,”staying in such a state even when accommodation isn’t needed—as when viewing in distance (at infinite distance).


Such near-work conditions, over time, may lead to a “spasm of accommodation,” where the ciliary muscle is in a state of chronic contraction, thus creating pseudomyopia or transient myopia.


Over time it usually gets worse and steady (it becomes an axial lengthening of the ocular globe). This result has its equivalent physiological explanation and is one of the ascertained causes for myopia development: a prolonged state of hyperopic defocus. According to the theory of defocus, the retina is subjected to repeated adaptations, depending on the position of focus. This simply means that the eye acts as a camera with an autofocusing system, constantly varying focus according to the distance of the observed object and therefore the position of focus—the position of the image on the retina.


According to the theory of retinal defocus, the condition of constantly maintaining the focus behind the retina, over time,

creates axial myopia, with the consequent lengthening of the ocular globe. This is the characteristic result of medium and high myopia. Such axial lengthening is the result of retinal adaptation(and eye length) to one excessively confined—in time and proximity—to that “near” environment.


Accepting this theory as the accurate one, the opposite can work as well: if the focus is maintained in front of the retina (creating
myopic defocus instead of the hyperopic one), the retina will constantly be trying to modify the focal level to the focal point, consequently stimulating the relaxation of accommodation that leads to better visual acuity and decreased myopia.

One of the principles of visual reeducation in the Power Vision System is based on this theory: using suitable retinal defocus we can lead the eye to adapt its refractive ability and decrease the initial refractive error until, possibly, compensating for the error. Such results have been obtained in experiments in many animals that were subjected to different states of retinal defocus.


Coming back to your question: one’s refractive ability directly depends on the quantity and the kind of optical stimuli she’s subjected to, either at near or in distance. According to the theory of accommodative balance, if the near-distance stimuli prevail, they may lead to myopia development.

There are two solutions for this problem:

1. Lessen (or eliminate) near-distance stimuli (changing the type of work with one that allows you to space your sight). This obviously isn’t an acceptable solution.


2. Don’t let your eyes be subjected to overaccommodative stress, even though you are carrying out near-work. You can obtain the latter result simply by wearing positive lenses whenever carrying out near-work. The process of accommodation has positive effects on focusing at near distance, allowing better focusing ability and visual acuity. Wearing positive lenses in near-distance activities, you can prevent your eyes from excessive near stimuli. This is a great protection against developing myopia.

The dioptric power of the lenses is to be calculated according to one’s refractive error and personal needs. An oculist or an optometrist should prescribe the right lens dioptric power.




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