Origins Of Visual Stress (Meares-Irlen Syndrome)

A teacher in New Zealand, Olive Meares, was the first to provide a detailed written account of the spatial distortions affecting text being read by some individuals.  Olive Meares also reported that the effects she cited could be reduced or eliminated by the use of coloured paper or by using coloured plastic overlays; the overlay is placed over the text to be read.

A psychologist working in California, Helen Irlen, wrote a paper describing symptoms similar to Olive Meares.  Ms Irlen, named the effects as Scotopic Sensitivity or Irlen Syndrome.  The syndrome was one in which reading is impeded by distortions of print. She reported that the distortions were positively effected if text was viewed through a coloured filter or overlay.  Ms Irlen went further and established a protocol for screening for scotopic sensitivity and a system for dispensing coloured overlays as a result of the assessment.

There followed a period of time during which the scientific community discussed these findings with a great deal of skepticism.  For instance, I was told by very senior psychologists that it was nonsense; the problem being that there was no satisfactory explanation as to why the treatment of visual distortion of text with coloured overlays should work.  Of course this did not mean that it did not work.  In fact medicine is littered with examples of treatments working first followed by an understanding of why much later.

Prof. Wilkins and colleagues of Essex University were amongst the first to apply scientific rigor to the study of scotopic sensitivity or Meares-Irlen Syndrome, as it had become known.  The Essex University team set up double blind placebo controlled trials and went on to establish a number of tools for screening for scotopic sensitivity and quantifying the effects of coloured overlays. 

The screening test is available to professionals and is know as the Intuitive Overlays Test.  Whilst the tool used to quantify the effects of overlays is also available to professionals and is known as the Wilkins rate of reading test.

In the past, assessment for scotopic sensitivity was generally done by the Irlen Institute.  It was quite an expensive assessment and the overlays were also relatively expensive.  Now the Intuitive Overlays Test combined with the Wilkins rate of reading test has enabled practitioners who have been trained by the Institute of Optometrists to carry out an assessment and prescribe an overlay for use when reading.  This has rolled out the number of professionals who have these assessment skills and made the assessment and prescription of suitable overlays much more affordable.

If you or your child is experiencing visual effects such as text wobbling, moving, flickering, blocking out, underlining, halo effects, head aches and/or a feeling of over brightness, then it would be useful to have an assessment in this regard.