Just as dyslexia itself is a highly emotive subject, so some of the remediation techniques advocated for dyslexics are equally controversial. One such treatment, the use of coloured lenses, is considered by some to make reading easier by counteracting the light-sensitive conditions which are believed to affect some children. There is growing interest in the use of coloured filters and lenses and the perceptual dysfunction referred to as scotopic sensitivity syndrome (SSS), which they are claimed to alleviate.