What is Dyslexia?
One of the most common definitions of dyslexia, as provided by the International Dyslexia Association (IDA), has recently been updated. Originally published in 2002, IDA defined dyslexia as a specific learning disability of neurobiological origin. It is characterized by difficulties with accurate and/or fluent word recognition, as well as 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 difficulties in reading comprehension and a reduced reading experience, which can hinder the growth of vocabulary and background knowledge.
Updated Definition
The most recent definition was released publicly at the IDA conference in October 2025. The new definition is as follows: Dyslexia is a specific learning disability characterized by difficulties in word reading, affecting accuracy, speed, or both, and/or spelling, which can vary depending on the written language system. These difficulties reflect performance at the low end of a continuum of literacy skill and occur despite evidence-aligned instruction that is effective for the individual’s peers.
The cause and development of dyslexia involve the interplay of multiple biological and environmental influences. Phonological and/or morphological difficulties are common but not always present. Among the secondary consequences are limitations in language development and academic progress, as well as challenges to psychological well-being and vocational opportunities. Although identification and targeted instruction are important at any age, language and literacy support before and during the early years of education could be particularly effective” (International Dyslexia Association, 2025).
Why the Change?
IDA has stated that significant research has been done in the last 20+ years since the 2002 definition was adopted. The new definition is an effort to reflect that research. There are other definitions of Dyslexia, and the National Institute of Health continues to identify dyslexia as a reading disorder in which individuals have difficulty linking speech sounds to letters and words, trouble with spelling and recognizing words, and difficulty with reading fluently.
How Common is Dyslexia?
The Yale Center for Dyslexia & Creativity estimates that 1 in 5 students has dyslexia. Dyslexia affects 15-20% of the population. Dyslexia falls under the category of a Specific Learning Disability, and about 80% of all students identified with a specific learning disability are believed to have dyslexia. Multiple studies indicate the presence of a neurobiological component to dyslexia.
Common Signs and Characteristics of Dyslexia
- Difficulty learning letter names and sounds
- Difficulty decoding words
- Slow, halting, or labored reading
- Problems with spelling and writing
- Difficulty recognizing and remembering sight words
- Poor phonological skills (such as rhyming, blending, and breaking words into their individual sounds)
Dyslexia is a spectrum disorder, meaning some people are mildly impacted and some people are severely impacted. Two common signs or characteristics that can be identified as early as kindergarten are difficulty with rapid automatic naming and difficulty with phonological awareness. Early intervention in these two key areas can improve basic reading skills. Just because someone has some of the signs and characteristics listed above does not necessarily mean they have Dyslexia. But these common signs do indicate that a student could benefit from evidence-aligned reading instruction.
Questions to Ask
Is your school using an explicit, cumulative, multisensory, evidence-aligned reading curriculum and instruction based on the science of reading?
The science of reading is a body of evidence based on thousands of studies that provide insight into how the brain learns to read. It is not a specific program; rather, it demonstrates that reading is a learned skill that requires explicit, systematic, and cumulative instruction, incorporating phonemic awareness, phonics, fluency, vocabulary, and comprehension. As of 2024, 40 states have passed Science of Reading laws; however, the laws vary by state, and not all states require their reading curricula to be evidence-based.
How does your school measure reading achievement and progress?
Schools should administer a universal beginning, middle, and end-of-year reading assessment. Phoneme segmentation fluency and nonsense word fluency scores in kindergarten and first grade provide data on a student’s ability with phonemic awareness skills. Starting mid-year in grade 1, elementary schools should be assessing oral reading fluency. DIBELS, AIMSweb, and Acadience all publish reference charts that explain what oral reading fluency scores should be for each grade level at the beginning, middle, and end of the year. Oral reading fluency is a good indicator of basic reading skills. This data can provide you with a good idea of how your child is performing compared to grade-level peers nationwide. Ask for these results. If you do not understand them, don’t hesitate to ask your child’s teacher to explain them to you.
If your child is struggling to read, are they receiving reading intervention at school?
Trust your gut! If your child is struggling to read, be proactive and don’t wait. Most schools have MTSS or RTI programs for students who require additional instruction, but these programs typically require students to qualify, usually based on reading assessments. Ask what specific skills your child needs to learn. Ask what reading intervention program your school is using, how much intervention your child is receiving, and how progress is being measured. Intensive explicit intervention that focuses on specific skill acquisition is frequently effective.
Be a Strong Advocate
If you are concerned about your child’s reading progress, or you suspect that they may have Dyslexia, contact your child’s teacher and put your concerns in writing. If they are not receiving intervention, request that your child receive reading intervention. Please work with your child’s teacher to track their progress and address any concerns. If your child’s reading skills are not improving after targeted intervention, request an evaluation. You can find additional resources on working with your school, as well as sample letters to request an evaluation, in the Partners in PROMISE Special Education binder.
About the Author
Barbara Bratton is an Educator and Certified Academic Language Therapist. She specializes in working with students with dyslexia and Specific Learning Disabilities in reading. She holds a Bachelor of Science in Elementary Education and Special Education. Mrs. Bratton also has a Master of Education in Special Education and Multisensory Structured Language Education. Mrs. Bratton has taught in Arizona, Maryland, and Colorado. She is Academic Language Therapy Association (ALTA) certified and completed her Dyslexia Specialist training through the Colorado Literacy and Learning Center. Mrs. Bratton has held a variety of elementary teaching positions and has extensive experience as a special education resource teacher, general education teacher, and reading interventionist. Mrs. Bratton is the author of Maggie with a G, her first book in a series about students successfully navigating school with various disabilities.
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