Old vs. New Dyslexia Definition Explained: A Parent’s Guide to the Proposed 2025 Update

Change is on the Horizon

For the first time in over 20 years, the International Dyslexia Association (IDA) has drafted a new definition of dyslexia. The way we define dyslexia matters because it guides how schools identify students, provide support, and shape policy. The IDA is asking for feedback from parents, educators, and other interested parties before the draft closes on September 2, 2025. This is a chance for families to share their voices, highlight real experiences, and help shape a definition that will influence how children with dyslexia are supported in schools for years to come.

Why Does the Definition of Dyslexia Matter for Families?

The definition of dyslexia shapes how schools decide who qualifies for help, how teachers provide instruction, and what kinds of special education services are offered.

For families, the wording can be the first step toward getting a child identified, supported, and provided with the right tools to succeed with literacy. Without a universally accepted definition of dyslexia, many children and young people risk being overlooked.

What Did the 2002 Definition of Dyslexia Say?

The previous definition from 2002, created by the International Dyslexia Association, states:

“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.”

What This Means:

• Dyslexia is a specific learning disability that begins in the brain (neurobiological in origin).

• It is marked by:

  • Trouble with accurate and/or fluent word recognition

  • Poor spelling

  • Difficulty decoding unfamiliar words

• These struggles usually come from problems in the phonological component of language (working with the sounds in words).

• The difficulties are often unexpected compared to:

  • A child’s other abilities

  • The instruction they have received in school

• Over time, this can lead to:

  • Problems with reading comprehension

  • Less reading overall, which may limit vocabulary and background knowledge.

What Does the 2025 Proposed Definition of Dyslexia Say?

The new definition of dyslexia (2025 draft) states:

“Dyslexia is a specific learning disability of developmental origin. It is characterized by difficulties with accurate and/or fluent word reading and spelling that persist despite effective instruction. The difficulties are often associated with deficits in phonological processing but may also involve broader challenges, such as morphology, that affect the acquisition of reading and spelling. Dyslexia may impact language development, attainment, and emotional well-being. Early identification and evidence-based instruction are critical to support individuals with dyslexia.”

What This Means:

• Dyslexia is a specific learning disability of developmental origin (present from early childhood).

• It is not caused by laziness or lack of effort.

• While poor instruction can make difficulties worse, dyslexia itself continues even when instruction is strong and effective.

• It is marked by:

  • Difficulties with accurate and/or fluent word reading

  • Spelling challenges

  • Struggles that persist over time, even with evidence-based teaching

• These difficulties are often linked to phonological processing (working with the sounds in words).

• They can also involve morphology (understanding word parts), which affects the acquisition of reading and spelling.

• Dyslexia may impact:

  • Language development

  • School progress

  • Emotional well-being

• The definition stresses the importance of:

  • Early identification

  • Evidence-based instruction and support for individuals with dyslexia

Old vs. New Definition of Dyslexia: What’s Different?

The chart below shows, in plain language, how the 2002 definition and the 2025 proposed definition of dyslexia describe causes, challenges, and support in different ways.

Category	2002 Definition (Old)	2025 Proposed (New)
Cause	• Brain-based only (neurobiological) • Seen as starting only in the brain	• Still developmental and brain-based • Adds the role of environment and reading instruction
Main Reading Challenges	• Trouble with word recognition • Poor spelling • Difficulty decoding unfamiliar words • Linked mostly to sound-processing (phonological)	• Keeps focus on reading and spelling • Adds fluency as a major challenge • Expands beyond sound-processing to include word parts (morphology)
Response to Teaching	• Struggles seen as “unexpected” • Based on the IQ gap (discrepancy definition)	• Shifts away from IQ gaps • Says struggles continue even after strong, evidence-based teaching • Applies across all ability levels
Other Effects	• May reduce reading comprehension • May limit vocabulary growth	• Keeps comprehension and vocabulary concerns • Expands to include school progress, confidence, and emotional well-being
Timing of Help	• Not strongly emphasized	• Adds strong emphasis on early identification and support

Why Do Experts Believe We Need a New Definition?

The International Dyslexia Association and other experts believe there is a need for a new definition because the previous one does not fully explain the wide range of ways dyslexia can appear in students. The goal of the new wording is to capture the full variety of challenges that both children and adults may face.

Here are some of the key areas the new wording brings into focus:

• The notion that dyslexia is only one type of profile is outdated.

• Dyslexia is a dimensional condition, ranging from mild to severe.

• The features of dyslexia include more than phonics—they also involve processing speed, fluency, and persistent learning difficulties.

• Dyslexia frequently co-occurs with one or more conditions, such as ADHD or developmental language disorder. This shows that the nature of the disorder is complex.

• The impact of dyslexia goes beyond reading, affecting long-term success in school and confidence.

  
  

Through a collaborative process, experts worked together to agree on a definition for dyslexia that better reflects what children and families experience in real life. That is why a new definition of dyslexia is now being proposed.

How the New Definition Fills the Gaps

The 2002 definition was important because it gave schools a clear way to identify dyslexia, mainly by looking at sound-processing skills and gaps between a child’s reading ability and their IQ. That wording became the basis for how many schools and specialists diagnosed dyslexia.

But over time, parents and professionals saw its limits. The 2002 definition did not cover all the different ways dyslexia shows up. It focused heavily on sound-processing, but didn’t mention other challenges like understanding word parts or how difficulties can continue even with strong teaching. It also didn’t stress the importance of early help or the emotional impact of ongoing struggles.

The new definition of dyslexia tries to address these gaps. It includes both the original pieces (such as sound processing and reading accuracy) and adds areas that were previously missing—such as fluency, the role of the environment, early support, and broader effects on school, long-term outcomes, and confidence.

What Could the New Definition Mean for Families?

• Dyslexia diagnosis: Instead of relying on the discrepancy definition tied to age and IQ, the focus may shift to criteria such as word recognition, fluency, and classroom progress.

• Eligibility for services: Because the new wording applies to students of all ability levels, more children and young people may qualify for dyslexia support and special education services.

• Consistency: Adopting a universally accepted definition of dyslexia could bring greater clarity across schools and states.

• Earlier support: The stronger emphasis on early identification may encourage schools to act sooner rather than waiting for children to fall behind.

• Focus on fluency: By including fluency in the definition, schools may place more attention on how smoothly and quickly students read, not just on accuracy.

• Emotional well-being: Since the new definition notes the emotional impact of dyslexia, schools may be more mindful of confidence, motivation, and self-esteem.

In short, the new definition could lead to earlier help, broader access to services, and a clearer, more complete understanding of how dyslexia affects children and families.

FAQ for Parents

Q: Why is there a need for a new definition of dyslexia?

A: The previous definition left gaps. The updated wording includes more statements about dyslexia and offers a wider understanding, reflecting the different ways children experience reading challenges.

Q: What are the key statements about dyslexia in the new draft?

A: The new definition explains that dyslexia is a developmental learning disorder that causes ongoing difficulties in reading, fluent word reading, and spelling, even when instruction is effective.

Q: Does dyslexia still mean it is brain-based?

A: Yes. Dyslexia is neurobiological in origin, meaning it starts in the brain, but environment and instruction also play a role in how reading difficulties develop.

Q: Does the new definition affect diagnosing dyslexia?

A: Yes. The focus is shifting away from the discrepancy definition (based on age and IQ) toward broader criteria that look at word recognition, fluency, and how a child responds to classroom teaching.

Q: Does the new definition make it easier to get a dyslexia diagnosis?

A: In many cases, yes. The update could bring more consistency in dyslexia assessment by focusing on a child’s reading and spelling progress rather than only IQ comparisons. This may reduce confusion about the criteria for dyslexia.

Q: Will the new definition change how schools provide special education services?

A: Possibly. The wording may broaden who qualifies for dyslexia support and special education services because it does not rely only on the discrepancy definition. This could help more children and young people access needed support.

Q: Will the new definition make support more consistent across schools and states?

A: That is the goal. A more universally accepted definition of dyslexia could create clearer expectations for schools and reduce differences in how districts approach support.

Q: What other challenges are associated with dyslexia?

A: Dyslexia can appear alongside other learning difficulties. In fact, it frequently co-occurs with one or more conditions such as ADHD or developmental language disorder.

Q: How does the new definition handle children with developmental language disorder?

A: The draft acknowledges that children with developmental language disorder may also show signs of dyslexia. This could encourage schools to consider overlapping challenges when identifying and teaching children.

Q: Does this affect older students and adults?

A: Yes. Dyslexia does not disappear with age. Older students and adults may still face challenges with reading and writing, which means they may need ongoing support, accommodations, or strategies to succeed throughout school and in daily life.

A Note to Parents

As someone following this update closely, I believe it’s important to say this: the 2002 definition of dyslexia gave us a starting point. It helped schools recognize dyslexia as real and provided a basis for services. But over the years, parents, teachers, and professionals have seen that it didn’t capture the full picture of what children and families experience.

The new definition of dyslexia is an attempt to expand and include more of those lived realities — things like fluency, the role of the learning environment, and the emotional toll. My hope is that this wording feels more aligned with what families see every day, and that it opens the door for better identification and stronger support for children with dyslexia at every stage.

What Parents Can Do Next

• Review the old vs. new definition of dyslexia carefully.

• Think about whether the key statements about dyslexia in the new draft match your child’s experience.

• Share your comments before September 2, 2025, at the public feedback link.