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About dyslexia

What is dyslexia?

Dyslexia is a specific learning difficulty which primarily affects reading and writing skills. However, it does not only affect these skills. Dyslexia is actually about information processing. Dyslexic people may have difficulty processing and remembering information they see and hear, which can affect learning and the acquisition of literacy skills. Dyslexia can also impact on other areas such as organisational skills.

It is important to remember that there are positives to thinking differently. Many dyslexic people show strengths in areas such as reasoning and in visual and creative fields.

Delphi definition of dyslexia

Dyslexia is a set of processing difficulties that affect the acquisition of reading and spelling.

In dyslexia, some or all aspects of literacy attainment are weak in relation to age, standard teaching and instruction, and level of other attainments.

Across all languages, difficulties in reading fluency and spelling are key markers of dyslexia.

Dyslexic difficulties exist on a continuum and can be experienced to various degrees of severity.

The nature and developmental trajectory of dyslexia depends on multiple genetic and environmental influences.

Dyslexia can affect the acquisition of other skills, such as mathematics, reading comprehension or learning another language.

The most commonly observed cognitive impairment in dyslexia is a difficulty in phonological processing (i.e., in phonological awareness, phonological processing speed or phonological memory). However, phonological difficulties do not fully explain the variability that is observed.

Working memory, processing speed and orthographic skills can contribute to the impact of dyslexia.

Dyslexia frequently co-occurs with one or more other developmental difficulties, including developmental language disorder, dyscalculia, ADHD, and developmental coordination disorder.

The journey to find a new definition of dyslexia

The Dyslexia Delphi Study aimed to establish ‘areas of consensus among a wide range of experts’ and to reduce ‘confusion and misinformation’ about how dyslexia should be defined.

The papers have been published in the Journal of Child Psychology and Psychiatry and the Dyslexia Journal.

Carroll, J.M., Holden, C., Kirby, P., Thompson, P.A., Snowling, M.J. and (2025), Toward a consensus on dyslexia: findings from a Delphi study. J Child Psychol Psychiatr. https://doi.org/10.1111/jcpp.1...

Holden, C., Kirby, P., Snowling, M.J., Thompson, P.A. and Carroll, J.M. (2025), Towards a Consensus for Dyslexia Practice: Findings of a Delphi Study on Assessment and Identification. Dyslexia, 31: e1800. https://doi.org/10.1002/dys.18...

It is important to note that the definition identifies the same or similar underlying cognitive indicators of dyslexia as the previous Rose (2009) definition, alongside recognition of its impact on individuals. For this reason, there is no suggestion that anyone diagnosed under the previous definition would not continue to meet the criteria for a diagnosis.