Friday, April 6, 2012

Irlen Syndrome - a visual stress syndrome

According to Wikipedia,
"Scotopic sensitivity syndrome, also known as Irlen Syndrome and Visual Stress Syndrome, approximating in some ways to Meares Irlen syndrome, and 'Visual Stress', refers to visual perceptual disorder(s) affecting primarily reading and writing based activities.

Scotopic sensitivity syndrome is based on the theory that some individuals have hypersensitive photoreceptors, visual pathways, and/or brain systems that react inappropriately to some wavelengths of light.

 In simple terms, the theory is that some signals from the eye are not getting to the brain intact and / or on time. Although the eye might be functioning correctly, the brain receives what is like a double exposed picture where the location of items is confused. The brain tries to filter out the bad information and so the conscious mind receives a reconstructed image. That image may be of the items moving (the brain constantly changing its best guess of what is there), blurred outcomes (inability to form a view of what is there), gaps in wrong spots, and a variety of other minor errors. There may also be exhaustion (from the mental effort to unscramble) and sore eyes (from the eyes constantly seeking extra data to aid the process) The problem is worst where different colours do not all give a similar outcome. In nature you get a lot of consistent data but on a man made item (e.g. paper) there might only be limited colour sets. i.e. The condition does not generate practical problems where there is lots of redundant data for the brain to use. The pragmatic response by Irlen was not to try to fix the problem but to avoid it. By filtering out the light most likely to generate problem signals to the brain, she was able to improve the likelihood that the brain will correctly distinguish between good and bad information. It also seems likely that in some individuals, over time the brain learns which colours are the problem items and improves its ability to reconstruct an accurate image."

1 comment:

  1. Hi,Christine, how are you?

    I'm from Brazil, and I've been reading your blog. Very good...! - because it shows a lot of information, in just one place, about Irlen Syndrome!!!! :-)

    I've realized that in Brazil there's few blogs and websites about Irlen Syndrome. (There are a lor of results in Google Search, in Portuguese; however, a lot of these results brings similar and "repeated" results in several homepages, instead of a wide range of new information about this, tips for patients and their parents, etc.)

    I'm the author of a Brazilian blog, "Sopa de Números na Educação Inclusiva" (, written in Portuguese; there are a lot of posts about handicapped people (especially in school/university) - and, among them, there are a lot of texts about Irlen Syndrome, written by me. (I've researched a lot of information at websites in English - and I wrote in Portuguese, to bring information to people in Brazil who doesn't understand English...) ;-) Take a look on it. (If you cannot read a text in Portuguese, try to use Google Translator to help you a little... ;-) )

    Congratulations for you blog! (And sorry if my English isn't good enough... (laughing).