Skepticism for Scotopic Sensitivity Syndrome

Skepticism surrounding scotopic sensitivity syndrome has evolved on several fronts:
Whether SSS exists as a distinct, predictably identifiable disease with a reasonable pathophysiological mechanism;

Whether SSS is causally or incidentally related to dyslexia, autism, or other conditions; and

Whether existing methods of SSS treatment are appropriate and effective.

The American Academy of Pediatrics (AAP) does not believe that there is any scientific evidence or basis for the use of colored lenses (the treatment used for SSS). When discussing its scientific basis, the AAP mentions that "the method used to select the lens or filter color has been highly variable,the color selection has also shown considerable variability,and the test-retest consistency has been poor"

The association of scotopic sensitivity syndrome and dyslexia has been challenged by many authors in both the optometric and ophthalmologic communities. Recent scientific evidence suggests a weak association.

    We have carried out a randomised prospective controlled trial of the effect of tinted lenses on the reading ability of 24 non-asthmatic dyslexic children aged between nine and twelve years. Reading ability was assessed using the Neale Analysis of Reading. After one school term, there was no significant difference in the change in reading age between treatment and control groups. After two school terms (approximately six months), only 11 children (44%) were still wearing the glasses. Of 381 suitable subjects for entry into the study, 208 were excluded because of a diagnosis of asthma (to avoid effects of medication on cerebral function). As a result, we may have excluded subjects who would have responded favorably to tinted lenses.

Critics claim that the symptoms of those with Scotopic Sensitivity Syndrome are related to already known visual disorders. According to a statement released by the American Optometric Association in 2004:

    There is evidence that the underlying symptoms associated with the Irlen Syndrome are related to identifiable vision anomalies, e.g., accommodative, binocular, and ocular motor dysfunctions, in many patients seeking help from colored lenses. Furthermore, such conditions return to normal function when appropriately treated with lenses, prisms, or vision therapy. When patients exhibiting the Irlen Syndrome were treated with vision therapy, their symptoms were relieved. These patients were no longer classified as exhibiting this syndrome, and therefore did not demonstrate a need for the colored overlays or tinted lenses.

This assessment has been criticised however for applying a self defining criteria to the tests which reached this conclusion.

A previous controlled study found the lenses not to significantly improve reading but several of its peer reviewed studies did find distinct neurological patterns in those displaying strong symptoms consistent with the syndrome.

Although experts are divided over the pathology of Irlen Syndrome, and whether it is a homogenous condition, or if instead several distinct syndromes are not being mistakenly placed under this loosely defined one, what is agreed is that for sufferers, the symptoms are very real. In a small minority of extreme cases they do appear quite pronounced, even acute. In other words, the symptoms on sufferers is not disputed by any recognised body of medical opinion, but there is a lively debate over exactly what is the cause and how to classify it. This is important to stress, because the impression may have been gathered from the discussion on this subject, that those displaying symptoms are in some sense 'faking it'. In truth very few researchers, and none of the most widely respected ones, believe this to be the case, nor have they ever suggested this."