The lure of the lens
When a parent or teacher is watching a child struggle to read, and dealing with tears every night at homework time, the promise of an easy cure and simple diagnosis is alluring. One of these promised cures is the use of coloured lenses or coloured transparent overlays to address visual sensitivity or processing difficulties aka. U2 head man Bono is particularly famous for wearing coloured or dark lenses. As much as I love U2 I’m going to have to recommend you don’t go trying to make your child look like Bono in the interests of solving his reading problems though.
Learning to read is a complex skill that requires high level interactions between dozens of different skill areas to work. In fact reading’s so complex it has even been shown to make physical changes to our brain structure. This complexity is why reading difficulties are so common. It’s a natural human tendency to want to reduce such complex problems down to simple solutions. However, in reviewing the evidence for the efficacy of coloured lenses or overlays for dyslexia, there are some large pitfalls that parents and teachers who want to help children with reading difficulties should be aware of.
The theory behind the use of coloured lenses for dyslexia is that reading difficulties are primarily caused by a visual-perceptual issue due to a weakness in the pathway of the visual system. People who support this theory claim that the cells in this pathway are sensitive to coloured light (especially yellow light). It is suggested that the use of coloured lenses in glasses or coloured transparent overlays placed over the text should correct visual ‘distortions’ (Ray, Fowler, & Stein, 2005) and remove ‘obstacles’ to reading (Irlen, 1991; 2010; Wilkins, 2003).
People who have been ‘prescribed’ coloured lenses or told they need to use coloured overlays are often told that they have Irlen’s Syndrome (also known as ‘visual stress’ or Meares-Irlen Syndrome). It’s important for parents and teachers to know that neither the International Classification of Disease (ICD-10; World Health Organisation) or the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association) list Irlen’s Syndrome (or any variant of it) as a recognised disorder. Neither of these manuals make any reference to visual-perceptual distortions as a symptom of dyslexia either.
By way of background, these manuals are considered by medical experts, educational psychologists, researchers and government bodies to represent the “gold standard” of classification for these types of disorders, as they are based on the accumulated weight of scientific evidence from thousands of peer-reviewed research studies. They are not infallible but they are robust tools that help to enhance consistent diagnostic practices.
Problems with the coloured lens
The first issue is in relation to the so-called ‘diagnosis’ of these visual difficulties. Currently evidence-based research indicates that dyslexia is a specific learning disorder which involves difficulties with phonological decoding, and accurate and fluent word recognition and is closely associated with language disorders (see more about specific learning disorders in the DSM 5 in our previous post here). In summary, there is no recognition of “Irlen syndrome” or related terms as a specific disability in the scientific community.
The second issue is that the efficacy of coloured lenses as treatment for reading difficulties is also highly contested. At this stage there is no scientific evidence to indicate that the use of coloured reading aides work. Despite this lack of evidence these so called “treatments” have received regular mass media exposure and their use has been increasingly accepted in schools with some teachers even starting to routinely recommend their use with any child who has a reading difficulty. In so-called Irlen clinics, pseudo-professionals may use a range of lofty sounding titles such as ‘diagnostician’, or ‘dyslexia expert’ which are not regulated and therefore can be self applied. It’s a well recognised sales/marketing strategy to give yourself a title that makes you sound like you have more credit than you actually do. If someone doesn’t have formal qualifications or registrations then there is a risk of these individuals just making one up. There a gazillion examples of this such as the dubious self-bestowed titles, “The Conversion Queen”, “7-Figure Goddess” and “Dr Sales” (OK I might be exaggerating a little). Some of these individuals are well intentioned and some are not but either way I’m instantly wary when someone self-dubs an authoritative title onto their name.
Appropriate diagnosis of specific learning disability and dyslexia needs to be performed by a health practitioner qualified to perform specialised psychometric testing (usually an educational psychologist) as well as a speech pathologist who can conduct a comprehensive language and literacy assessment. Treatment can be provided a team of professionals including speech pathologists depending on the specific areas of difficulty a student is experiencing. These professionals are all University trained, regulated by professional bodies and have professional and ethical standards by which they need to abide. At Chatterbugs our professional title of Certified Practicing Speech Pathologist is a designated title given by Speech Pathology Australia to appropriately trained practitioners who abide by a high set of professional and ethical standards including a demonstrated commitment to ongoing professional education.
Research studies published in peer-reviewed scientific journals have consistently found there is insufficient credible evidence that coloured lenses improve reading difficulties (McIntosh & Ritchie, 2012). More than that, many Irlen-based studies tend to only include individuals who have previously been using the lenses, meaning that results are biased towards finding a positive report (Albon, Adi, & Hyde, 2008).
What’s particularly puzzling from a scientific point of view, is that several Irlen studies overlook the importance of using a control group (i.e., comparing children with coloured lenses to children with just plain lenses). High quality evidence for a treatment needs to not only demonstrate improvement, but demonstrate that improvement is due to the specific consequence of the treatment, and not just by chance or other factors such as natural development which is why a control group is so important.
Additionally, review of the statistical methods and techniques used in the studies to date suggests that the authors tend to use methods that increase the likelihood of finding a positive result (Hyatt, Stephenson, & Carter, 2009). In scientific circles this is often called ‘data snooping’ and is basically when a researcher simply picks the best results, and ignores or deletes the rest. The difficulty with this is not only does it misrepresent the real results it makes it virtually impossible for other researchers to replicate those same results.
Points of Proof
There are 3 basic points of proof that a treatment needs to be able to show in order to “show it works”:
- The treatment changes the thing it’s meant to
- Those treatment changes can’t be explained by chance or other factors
- Other people can reproduce those same results again and again
To date, research on the efficacy of coloured lenses for dyslexia has failed to provide any of these 3 points of proof. Now, it seems unlikely that wearing coloured lenses or using a coloured piece of plastic over a page a child is reading would directly harm children who have dyslexia so there is probably no reason to avoid even trying the use of these aides. BUT, if by going down this track it leads to a lack of appropriate interventions to support the child’s learning, then there is a clear potential for real and lasting harm by preventing them from getting the treatments they really need. I’ve personally witnessed this with adults who were “diagnosed” with Irlen syndrome as children and continue to experience significant ongoing literacy difficulties as adults because parents felt like they had gotten their child the ‘treatment’ they needed. That makes me mad – it’s not right and it’s not fair.
Hang on though…
Given my professional stance on Irlen syndrome it might seem strange but I actually sometimes use coloured transparent rulers with children who have reading difficulty. Why? Well, I’ve noticed that sometimes this ruler makes it a little bit easier for a child keep visual attention on the words they are reading. It also makes the reading activity a bit more interesting and fun, which we know helps kids learn better. But I don’t use it as a “treatment”. It is a tool or a strategy I use the same as I would use a specific game or resource for a specific child, not because it is a “treatment” but because it’s a way to engage the child in the treatments they actually need such as improved segmenting, blending or reading fluency skills.
So, if you have a child with reading difficulty, ensure you get a comprehensive assessment battery completed by a team of suitably qualified professionals and then follow it up with treatments for the difficulties that are identified. If you want to try a bit of coloured plastic to see if it helps by all means give it a go but make sure you ensure you child also has access to the specific treatments that have been shown to actually help children with reading difficulties.
- Albon, E., Adi, Y., & Hyde, C. (2008). The effectiveness and cost-effectiveness of coloured filters for reading disability: A systematic review. West Midlands Health Technology Assessment Collaboration, Department of Public Health and Epidemiology, University of Birmingham.
- Hyatt, K. J., Stephenson, J., & Carter, M. (2009). A review of three controversial educational practices: Perceptual motor programs, sensory integration, and tinted lenses. Education and Treatment of Children, 32(2), 313-342.
- Irlen, H. (1991). Reading by the colors: Overcoming dyslexia and other reading
- disabilities through the Irlen method. NewYork, NY: Avery Publishing Group.
- Irlen, H. (2010). The Irlen revolution: A guide to changing your perception and your life. New York, NY: Square One Publishers.
- McIntosh, R. D., & Ritchie, S. J. (2012). Rose-tinted? The use of coloured filters to treat reading difficulties. Neuroscience and Education: The Good, the Bad, and the Ugly.
- Stein, J. (2003). Visual motion sensitivity and reading. Neuropsychologia,41(13), 1785-1793.
- Wilkins, A. J. (2003). Reading through colour.Chichester, UK: Wiley.