What is Dyslexia?

A Guide to Understanding

The diagnosis is clinical.
The treatment is educational.
The understanding is scientific.

~M. Rawson


Dyslexia is a specific learning disability. It is an inherited condition that is neurological in origin, which hinders the acquisition of reading and writing skills. Dyslexia is a language-based disorder that does not arise from a physical limitation or developmental disability. Students with dyslexia may be identified as having a Specific Reading Disorder, Specific Writing Disorder, Specific Mathematics Disorder or Language Learning Disability ; however, not all dyslexics may meet the criteria for special education resources. Dyslexia may present with varying degrees of severity.



There are many definitions of dyslexia. These two definitions encompass the traditional positions used by schools and professionals in the field of education.

International Dyslexia Association


Dyslexia is a specific learning disability that is neurobiological in origin. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede the growth of vocabulary and background knowledge.

Adopted by the International Dyslexia Association, U.S.A., Board of Directors, Nov. 12, 2002.

Sir Jim Rose Report, U.K. 2009

  • Dyslexia is a learning difficulty that primarily affects the skills involved in accurate and fluent word reading and spelling.
  • Characteristic features of dyslexia are difficulties in phonological awareness, verbal memory and verbal processing speed.
  • Dyslexia occurs across the range of intellectual abilities.
  • It is best thought of as a continuum, not a distinct category, and there are no clear cut-off points.
  • Co-occurring difficulties may be seen in aspects of language, motor co-ordination, mental calculation, concentration and personal organisation, but these are not, by themselves, markers of dyslexia.
  • A good indication of the severity and persistence of dyslexic difficulties can be gained by examining how the individual responds or has responded to well founded intervention.

From Identifying and Teaching Children and Young People with Dyslexia and Literacy Difficulties, Sir Jim Rose Report, 2009, Part 2, Chapter 1, p.29.


Dyslexia is characterized by deficits or difficulties in the following areas:

  • Phonological processing
  • Letter-sound relationships
  • Spelling
  • Word recognition
  • Reading fluency
  • Handwriting

Secondary consequences of weaknesses in the above areas may include:

  • Vocabulary knowledge
  • Reading comprehension
  • Mathematics



  • difficulty learning the alphabet
  • confuse letters, sounds, e.g. b/d, g/q
  • reverses letters or sounds within words
  • have difficulty blending sounds into syllables
  • have difficulty sounding out words
  • omits or inserts words in sentences
  • reads with difficulty
  • reads without expression
  • does not obey punctuation when reading
  • avoids reading


  • incorrect letter formation
  • makes spelling mistakes, even in simple short words
  • does not apply or understand spelling rules
  • spells phonetically
  • cannot memorize Sight Words
  • written expression is below grade level


  • difficulty learning math facts
  • difficulty learning a sequence of math operations
  • difficulty with directionality
  • reverses numbers, e.g. 6/9 or 15/51
  • difficulty with geometry


  • late talker
  • difficulty listening and following instructions
  • difficulty recalling words or labels
  • articulation issues, e.g. f/th, d/t
  • difficulty rhyming words or syllables

What can be done?

Difficulties in reading, writing and mathematics resulting from dyslexia can be remediated. Programmes based on the Orton‑Gillingham Approach can bring about profound improvements in the academic life of a dyslexic child or adult.

The Orton‑Gillingham Approach is systematic and multisensory. Through guided discovery and direct language instruction in pivotal areas, such as, phonemic awareness, alphabet knowledge, phonics, reading fluency and vocabulary development, students learn to read and spell.

The key to progress and skill improvement is early diagnosis and appropriate intervention. Having dyslexia need not prevent students from achieving success and realizing their dreams.