It is claimed that the use of coloured filters and lenses can alleviate visual distortions for people with dyslexia. These overlays are simple translucent pieces of plastic which add colour to text. But I believe they should not be recommended as a treatment or a form of support for people with dyslexia because there is a lack of convincing scientific evidence supporting their effectiveness.
What troubles me as a research specialist in dyslexia, as well as being dyslexic myself, is the proliferation and abundance of advertisements and testimonies proclaiming the effectiveness of the treatment online, including websites and magazines which are produced by nationally recognised dyslexia focused charities.
In fact, a 2014 survey published in the British Medical Journal found that six out of eight UK dyslexia organisations were promoting such products on their websites uncritically and in an unbalanced way.
I believe that promoting the use of these coloured filters gives people with dyslexia false hope. Those who work in this field should, instead, be focusing on the delivery and promotion of evidence-based interventions, such as the systematic teaching of letter to sound combinations (phonics), or the provision of technology supports such as text to speech software.
What is dyslexia?
Dyslexia is a neurological condition affecting between 7-10% of the population. It is a learning disability which has an impact on a person’s ability to learn how to read and write (despite adequate intelligence and educational opportunities).
Research has demonstrated that people with dyslexia often have difficulty processing and representing the specific sounds of language. As a result, someone with dyslexia will experience difficulties in associating printed letters with relevant speech sounds, thus causing reading difficulties.