FYI: Sorry, but these types of eye exercises and lens therapies have been scientifically studied.
Unfortunately, they do not work. There is some evidence that plus lenses MAY slightly reduce the rate of
progression of myopia for a limited time in kids. But otherwise, they don't seem to work.
I realize that there is some controversy regarding whether plus lenses and "undercorrection" really do work. My personal experience and that of others is these therapies work quite effectively, when done properly and for long enough. However, many have challenged whether this is scientifically possible.
First, I agree with Cindy that lens therapies are quite distinct from eye exercises such as the Bates method and should not be confused with these. There is significant evidence, primarily from animal studies, that myopia can be both caused and corrected by the use of lenses, based upon the Incremental Retinal Defocus Theory (IRDT). The process of elongation of the eye is called "emmetropization". As I elaborated upon on the Rehabilitation
page of my blog, those studies show that animals fitted with plus lenses undergo hyperopic growth which compensates for myopia. This is confirmed both by focusing tests and by physiological evidence that the stimulus of "retinal-image defocus" actually impacts neuromodulators, proteoglycan synthesis, and the integrity of "scleral structure" in the eye, resulting in the elongation of the eye and causing myopia.
Nevertheless, the efficacy of lens therapies has been questioned, at least for humans. For example, there is a key paper by Chung, Mohidan and O'Leary (http://tinyurl.com/chung22
) which found that myopic children fitted with undercorrected lenses showed a more rapid progression of myopia than children wearing lenses with full correction. So the eyesight of these children actually got worse
by using undercorrection than normal correction. This would appear to contradict the IRDT hypothesis that the eye can be stimulated via lens therapy to grow shorter in axial length, and hence reduce myopia. And this result has been repeatedly cited by others as disproving the effectiveness of plus lenses or undercorrection.
However, a re-analysis of this study by Hung and Ciuffreda of Rutgers University (http://abstracts.iovs.org/cgi/content/abstract/44/5/4791
) came to a different conclusion. In addition to normal correction and slight undercorrection groups, the Hung and Ciufredda study included a group using "high-powered plus lenses". Their analysis found that the high-powered plus lenses led to hyperopic
growth (in other words, shortening of the eye's axial length), which decreased the myopia of the children wearing those lenses. And the progression of myopia in children who wore undercorrected lenses is explained by the fact that they wore these all the time, not when just reading. This led to a diminished stimulus by facilitating accommodative focuses during "near-to-far viewing cycles", which underminded the benefits of undercorrection.
Based upon this analysis, the proper use of undercorrection would be to wear the undercorrective lenses only
during long distance viewing. This is a key point! Note that, according to the protocol of the study by Chung et al (p. 2556):
Subjects were instructed to wear their glasses all the time except during sleeping.
The fact that the undercorrected lenses were worn for close up viewing as well as distance viewing, would tend to undermine their effectiveness, according to the IRDT theory.
In summary, Hung and Ciufredda conclude:
Based on IRDT analysis, high-powered plus lens, full correction, and 0.75 D under-correction result in relative hyperopic, emmetropic, and myopic growth, respectively. Thus, the theory is able to explain these apparently contradictory findings. Moreover, the IRDT provides a consistent theoretical framework for understanding the development of myopia under a variety of experimental and clinical conditions.
So far from disproving the value of plus lenses and undercorrection, this study supports the IRDT theory for treating myopia. The conclusion should be taken as showing how NOT to use undercorrected lenses -- don't wear them for close work and reading, only for far distance viewing activities such as driving. On the other hand, for close work (reading and computer use), wearing stronger plus lenses are effective in counteracting myopia. Based upon IRDT theory, I suppose the ideal combination would be bifocals with plus lenses for close vision and undercorrection for distance vision, or using two different glasses for these different situations.