The IDA periodically updates the definition to reflect current scientific and clinical research. The new definition offers shared language and a clearer framework for educators, clinicians, researchers, parents and students.
If you didn’t already know: since 2025, the dyslexia community has a new, more detailed definition of dyslexia. The International Dyslexia Association, known as the IDA, operates as a central authority on this specific learning disability. Through things like advocacy, awareness, research, professional development, and establishing educational standards, the IDA has been instrumental in helping students with dyslexia and their families. Understanding what dyslexia encompasses is such an important part of the journey with this learning disability; this definition helps to dive deeper into causes, symptoms, and effects. Do you have a student with dyslexia? You might want to learn more about the 2025 definition. Read on to learn the answers to 7 FAQs about the new dyslexia definition.
The International Dyslexia Association periodically updates its working definition of dyslexia to reflect the latest scientific, clinical, and educational research. As our understanding of learning differences grows, the definition must grow with it. A current, research-aligned definition gives educators, clinicians, parents, researchers and students a shared language for understanding what dyslexia is — and what it is not. A broader and more accurate definition also matters in real-world practice. When definitions are too narrow, dyslexia can become unintentionally “pigeonholed” in legislation, policy or court cases, limiting who qualifies for support and how services are delivered. Updating the definition helps ensure that guidance, interventions, and legal protections reflect the full complexity of dyslexia as it presents in students today. By expanding the definition to include new research findings and lived experiences, IDA provides a clearer and more actionable framework for identification, intervention and advocacy. This ultimately helps create more consistent support for students with dyslexia across schools, states, and systems.
The new dyslexia definition, as written by the IDA, was adopted on October 22, 2025. Here it is, word for word: “Dyslexia is a specific learning disability characterized by difficulties in word reading and/or spelling that involve accuracy, speed, or both and vary depending on the orthography. These difficulties occur along a continuum of severity and persist even with instruction that is effective for the individual’s peers. The causes of dyslexia are complex and involve combinations of genetic, neurobiological, and environmental influences that interact throughout development. Underlying difficulties with phonological and morphological processing are common but not universal, and early oral language weaknesses often foreshadow literacy challenges. Secondary consequences include reading comprehension problems and reduced reading and writing experience that can impede growth in language, knowledge, written expression, and overall academic achievement. Psychological well-being and employment opportunities also may be affected. Although identification and targeted instruction are important at any age, language and literacy support before and during the early years of education is particularly effective.”
That is a LOT, right? Let’s break it down so some terms and ideas can be clearly understood.
Orthography refers to the structure of written language — the rules and patterns that govern how writing works. It includes spelling, the relationship between written symbols and the sounds they represent, capitalization, punctuation and the conventions that help readers make sense of text. Because it ties together sound, symbol and meaning, orthography plays a central role in both reading and writing development.
The inclusion of this term is a great improvement in the definition. It’s so important to know that being diagnosed as dyslexic is not a simple, straightforward label. This condition exists on a spectrum for students, and it can range from mild to moderate to severe. With this new definition, it is hoped that students on all levels of the continuum will receive the right kind of tailored support for dyslexia.
One of the most important shifts in the updated definition is its expansion beyond a singular focus on phonological deficits. Earlier definitions emphasized the neurobiological origin of dyslexia — and that remains true — but the new definition widens the lens to recognize the influence of both neurobiology and environmental conditions, including the quality and consistency of reading instruction. This broader framing matters. It acknowledges dyslexia as a complex learning disability shaped by multiple interacting factors. It also reflects what research and clinical practice have shown for years: inadequate instructional opportunity can complicate identification and can sometimes mimic or mask the underlying characteristics of dyslexia. Including environmental factors in the definition helps clarify these distinctions and ensures that students are evaluated within the full context of their learning experiences. By expanding the definition in this way, the IDA creates space for a more accurate and comprehensive understanding of dyslexia — one that supports better identification, better instruction and stronger advocacy for students who need intervention.
This addition to the new definition is especially important because it expands the conversation beyond academics and reading skills. While dyslexia can affect comprehension, written expression and overall academic achievement, the impact often extends further. Students may experience emotional and long-term secondary consequences, including anxiety, low self-esteem and depression — challenges that frequently develop after years of frustration or misunderstanding. The updated definition also acknowledges that dyslexia can have implications well into adulthood. Difficulties with reading and written language may influence employment options, workplace confidence and daily functioning. This broader perspective underscores that dyslexia is not solely an academic concern but a lifelong learning profile with wide-reaching effects. By naming the social-emotional and long-term consequences directly, the new definition reinforces the need for holistic support that addresses both academic skills and emotional well-being. This shift helps ensure that students and adults with dyslexia receive comprehensive, meaningful interventions across all stages of life.
While the IDA serves as the gold standard for so much in the dyslexia world, Dyslexia on Demand, with the implementation of Orton-Gillingham curricula and a holistic approach is the gold standard for dyslexia therapy. One-on-one online sessions with Dyslexia on Demand are led by highly trained Certified Academic Language Therapists (CALTs). This method helps to directly target many of the underlying core difficulties of dyslexia by using evidence-based, specialized instruction.
At Dyslexia on Demand, our aim is to re-wire the brain so that students can build new pathways for reading and spelling. Our multisensory approach engages students; Sessions are frequent and intensive, working to build fluency and comprehension. Not only that, dyslexia therapy can help students to build confidence and learn self-advocacy in the classroom and in the real world. Reach out to Dyslexia on Demand to discover more about dyslexia therapy.
No. While the IDA’s definition informs best practices, school-based identification still follows state guidelines, evaluation teams and federal frameworks such as Section 504 or IDEA.
Eligibility decisions remain local, but the expanded description helps guide more precise intervention planning and may help schools better recognize a wider range of dyslexia characteristics.
Yes. The IDA emphasizes that identification and targeted instruction matter at any age, and that support given later in life can still improve reading, spelling and confidence.
References
International Dyslexia Association. (2025). IDA Dyslexia Definition (2025): Updated working definition and explanatory framework. International Dyslexia Association. https://dyslexiaida.org
International Dyslexia Association. (2023). Dyslexia basics. International Dyslexia Association. https://dyslexiaida.org/dyslexia-basics
International Dyslexia Association. (2023). Dyslexia fact sheets: Understanding characteristics, identification, and intervention. International Dyslexia Association. https://dyslexiaida.org/fact-sheets
Shaywitz, S. E., & Shaywitz, B. A. (2020). Overcoming dyslexia: A new and complete science-based program for reading problems at any level (2nd ed.). Alfred A. Knopf.
Moats, L. C. (2020). Speech to print: Language essentials for teachers (3rd ed.). Paul H. Brookes Publishing.
Snowling, M. J. (2019). Dyslexia: A very short introduction (2nd ed.). Oxford University Press.
Catts, H. W., & Kamhi, A. G. (2017). Language and reading disabilities (3rd ed.). Pearson.
National Center on Improving Literacy. (2022). What is dyslexia? Research-based guidance for families and educators. U.S. Department of Education. https://improvingliteracy.org
Gaab, N. (2017). The neurobiology of dyslexia: Early identification and implications for intervention. Developmental Cognitive Neuroscience, 27, 1–7. https://doi.org/10.1016/j.dcn.2017.08.001
Scarborough, H. S. (2001). Connecting early language and literacy to later reading (dis)abilities: Evidence, theory, and practice. In S. B. Neuman & D. K. Dickinson (Eds.), Handbook of early literacy research (Vol. 1, pp. 97–110). Guilford Press.
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