What is Dyslexia?

The Dyslexia Association adopts the Delphi Definition of Dyslexia:

Nature

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

Manifestation

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

Impact

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 languages and age groups, difficulties in reading fluency and spelling are a key marker of dyslexia.

Variance and Co-occurrence

Dyslexic difficulties exist on a continuum and can be experienced to various degrees of severity. Dyslexia can affect the acquisition of other skills, such as mathematics, reading comprehension or learning another language. Dyslexia frequently co-occurs with one or more other developmental difficulties, including developmental language disorder, dyscalculia, ADHD, and developmental coordination disorder.

 

Carroll, J., Holden, C., Kirby, P., Snowling, M. J., & Thompson, P.A. (2025) Journal of Child Psychology and Psychiatry.

 

  • Dyslexia is one of a family of Specific Learning Difficulties.
  • Many people who have dyslexia have strong visual, creative and problem solving skills.
  • Dyslexia is not linked to intelligence but can make learning difficult.
  • Dyslexia is a life-long condition which has a substantial effect on an individual’s day to day activities and is classed as a disability under the Equality Act 2010.
  • Dyslexia varies from person to person and no two people will have the same set of strengths and weaknesses.
  • It often co-occurs with related conditions, such as dyspraxia, dyscalculia and attention deficit disorder.
  • Dyslexic individuals often have difficulty processing and remembering information