2003 IMTA Proceedings - International Military Testing Association

Individualized colored filters seem to return the balance between the two processing systems,
preventing this overlapping (Robinson, 1994). The colored overlays and filters cut down or
eliminate the perceptual problem by screening out the wavelengths of light troublesome to
the individual (Sims, 1999). Studies of both the long- and short-term efficacy of the
transparencies and filters have shown that they do, indeed, provide benefits to the individual
afflicted with SSS (Whiting, Robinson, & Parrott, 1990; Robinson & Conway, 1990).
THREE STUDIES
Although there have been numerous studies into perceptual dyslexia since its
recognition in 1983, we will look at just three in this paper: Irvine, Lewine, and Wilkins.
Irvine’s Experiment for the Navy
The Navy wanted to see if the visual performance of those afflicted with perceptual
dyslexia changed as the energy spectrum presented to them changed. Therefore, in 1995,
James Irvine conducted an experiment at China Lake, California, that showed that for certain
perceptual dyslexics the receptor fields do NOT sum to unity, so the image sent to the brain
is not crisp and clear. When this happens, the subject’s visual control system alters radically,
so the subject does not see the image properly. (Irvine & Irvine, 1997)
Lewine’s Study
In the late 1990s, Dr. Jeffrey Lewine, a neuroscientist then at the University of Utah
Center for Advanced Medical Technologies, discovered that modifying the light frequency
spectrum that went to a perceptual dyslexic’s vision system could make the brain alter and
revert to a more normal brain pattern. He also noted that he could actually cause five to six
percent of the “normal” population to develop dyslexic-type dysfunction when they were
exposed to “abnormal” light frequency environments. (Lewine, et al., in press) This means
that some ordinarily non-dyslexic personnel can develop gross inefficiency, degraded
performance, and/or become dysfunctional and unable to perform normally under certain
lighting conditions such as red battle lighting, blue precision operating bays, or in foggy or
hazy conditions.
Wilkins’ Studies
Professor Arnold Wilkins, while a research scientist at the Medical Research Council
Applied Psychology Unit of Cambridge University in the United Kingdom, studied the
neuropsychology of vision, reading and color, photosensitive epilepsy, and attention,
conducting double-blind experiments to validate the existence and potential treatment of
perceptual dyslexia. He did this using four different groups of readers, mostly children,
randomizing the presentation order of the overlays, and further randomizing the use of the
appropriate overlays versus placebo overlays. (Wilkins, 2003)
Wilkins’ studies determined that, when given the choice, about half the readers would
choose clear overlays, and the other half would choose the colored overlays. Given that only
45 th Annual Conference of the International Military Testing Association
Pensacola, Florida, 3-6 November 2003
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