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What is Dyslexia (Reading and Spelling Disorder)?
Reading and spelling disorder (dyslexia), also known as dyslexia or dyslexia, is a neurobiological developmental disorder that impairs the ability to quickly and accurately recognize and process written words. It is not the result of low intelligence or inadequate instruction, but an innate difference in the neurological processing of written language. People with dyslexia typically have difficulties decoding words, writing, and sometimes spelling – regardless of their IQ or educational level.
According to estimates by the World Health Organization (WHO), reading and spelling disorder affects approximately 5-10 percent of the world's population. In Germany, approximately 4-5 percent of all students are estimated to have a diagnosed dyslexia. However, the actual prevalence could be higher, as many cases remain undiagnosed.
Important to understand: Dyslexia is not a sign of laziness or lack of intelligence. Many highly gifted people have a reading and spelling disorder. Neuroscientific research shows that it is a difference in brain structure and function – particularly in areas responsible for language processing.
For digital accessibility, understanding dyslexia is essential: People with dyslexia require special accommodations when using websites and digital content to have equal access to information.
5-10% of the world's population have a reading and spelling disorder
It is a neurological developmental disorder, not a sign of lack of intelligence
Symptoms can persist throughout life, but are manageable through appropriate accommodations
Neurological Foundations and Causes
The neurobiological basis of dyslexia lies in differences in brain processing of written characters. Research using imaging (fMRI) shows that people with reading and spelling disorders show reduced activation in brain areas responsible for language processing – particularly in regions responsible for phonological processing (sound processing) and visual word form recognition.
The causes of dyslexia are multifactorial and partially genetic. Research suggests that multiple genes are involved in the development of reading and spelling disorders. If one or both parents have dyslexia, the risk for children is increased. However, dyslexia is not simply "hereditary" – environmental factors also play a role.
A core problem in dyslexia is weakness in phonological processing. This means that people with reading and spelling disorders have difficulty breaking words down into their individual sound components and reassembling them. This directly impairs the ability to decode unfamiliar words and spell correctly.
Additionally, differences in visual perception of written characters can play a role. Some people with dyslexia report phenomena such as "visual stress" – letters appear blurred, disappear, or move around on the page. This experience is real and measurable, even though physical vision is normal.
Symptoms and Manifestations
The symptoms of reading and spelling disorder vary in severity and intensity. Not all people with dyslexia show all listed symptoms. An essential characteristic is the persistence of symptoms – they do not simply improve with more practice or better instruction.
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Reading disorder: Difficulty reading fluently, frequent confusion of similar-looking letters (b/d, p/q), omission or addition of letters, slow reading speed
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Spelling: Frequent and persistent spelling errors, difficulties with word-sound mappings, problems writing complex or irregular words
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Writing: Difficulties organizing sentences, disorganized or confused written structure, difficulties automating writing processes
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Phonological processing: Difficulties rhyming, breaking words into sounds, or combining sounds into words
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Memory retrieval: Difficulties retrieving word or number sequences (e.g., alphabet sequences, multiplication tables)
Diagnosis and Early Detection
A reliable diagnosis of reading and spelling disorder requires comprehensive psychodiagnostic examination by specialized professionals and methods, such as school psychologists, educators, or speech therapists. Development should be observed early in children at school. Support for children's competency development is important in school.
Standardized Tests: There are established tests for assessing reading and writing performance, such as the "German Writing Tests" (DST), the "Salzburg Reading Screening" (SLS), or tests like the "Test of Reading Comprehension". These tests measure both speed and accuracy in reading and writing.
Phonological Tests: Special tests measuring phonological processing, sound memory, and rhythmic intelligence help identify the cognitive roots of problems.
Intelligence Test: A central criterion for diagnosing dyslexia is the exclusion of general cognitive impairments. An intelligence test helps clarify that the reading disorder is not the result of general intellectual disability, but rather represents a specific weakness in written language processing.
Early Detection in Kindergarten and Elementary School: Those identified early can benefit from targeted interventions sooner. Warning signs in kindergarten include difficulties with rhyming, delayed speech development, or difficulties learning letters.
Reading and Spelling Disorder and Digital Accessibility
For people with dyslexia, digital accessibility is not an added service, but a necessity. Websites and digital content that are not designed with accessibility in mind create additional barriers and increase the time needed to understand information.
Typical problem areas on the web: Small font sizes, tightly packed text without breaks, unfavorable color combinations, complex sentence structures, lack of content organization (missing headings and bullet points), and auto-playing text (which further complicates the reading experience).
The Web Content Accessibility Guidelines (WCAG) contain several success criteria that are essential for people with reading and spelling disorders – particularly Criterion 3.1.5 "Reading Level", which requires that text be written at a level below high school reading level.
The Accessibility Strengthening Act (BFSG), which came into force on June 28, 2025, requires companies to make their digital offerings accessible to all – including people with reading and spelling disorders.
Best Practices: Website Design for People with Dyslexia
These best practices ensure your website is accessible and usable for people with reading and spelling disorders.
Clear Typography and Font Design
Use dyslexia-friendly fonts such as OpenDyslexic, Dyslexie Font, or Arial. Avoid serif fonts like Times New Roman. Increase font size to at least 12-14px for body text. Use generous spacing between lines (at least 1.5x) and between letters.
Structured and Understandable Content
Use meaningful headings, short paragraphs, and bullet lists. Avoid extremely long sentences and complex sentence structures. Use images, icons, and infographics to support text comprehension. Emphasis should be bold or underlined, not just colored.
Text-to-Speech and Alternative Formats
Integrate text-to-speech functionality so users can have text read aloud. Offer PDF content also in HTML format. Provide transcripts for audio and video content. Enable download of content in customizable formats.
SiteCockpit Solution
How easyVision Supports People with Dyslexia
easyVision offers specialized features that directly help people with reading and spelling disorders. With a text-to-speech function, users can have text read aloud automatically. The widget allows adjustment to dyslexia-friendly fonts, increase font size, increase line spacing, and adjust contrast. Users can also disable animations to reduce visual distractions.
Support and Intervention Methods
Reading and spelling disorder is not curable, but highly manageable with appropriate interventions. Early detection and specialized support can significantly reduce its effects.
Specialized Coaching and Tutoring: Structured training programs such as "Structured Reading and Writing" (SLS), which focus on developing phonological awareness, have proven effective. Multisensory approaches – involving multiple senses – often produce better results than traditional teaching methods.
Assistive Technology: Text-to-speech software, dictionary apps, spell-checkers, and special e-readers with adjustable fonts are effective tools. These technologies should not be understood as "crutches," but as necessary accommodations that enable people with dyslexia to participate equally.
School Accommodations: Children with diagnosed dyslexia have a right to legal accommodations in school. These can include extra time on exams, use of spell-checkers, oral rather than written exams, or other adapted assessment methods. Support for affected children at this age is crucial.
Emotional and Psychological Support: Many people with dyslexia develop avoidance behavior or low self-esteem regarding their reading abilities. Psychological support and a supportive environment are essential for long-term success.
Dyslexia in Everyday Life: Strengths and Perspectives
While dyslexia comes with challenges, many people with reading and spelling disorders also have special strengths. Research shows that people with dyslexia often have above-average abilities in spatial thinking, creativity, problem-solving, and visual arts.
Notable Figures with Dyslexia: Many successful people had or have dyslexia – artists, scientists, entrepreneurs, and athletes. These examples demonstrate that dyslexia does not impair the ability to achieve great accomplishments.
Career Prospects: With adapted technologies and proper support, people with dyslexia can succeed in virtually any profession. Some careers – such as architecture, engineering, design, or artistic pursuits – actually play to the visual strengths many people with dyslexia have.
Neurodiversity Perspective: Increasingly, dyslexia is understood not merely as a "deficiency," but as part of human neurological diversity. This perspective emphasizes that people with dyslexia think and process differently – not worse.
Relevant WCAG Success Criteria
The Web Content Accessibility Guidelines (WCAG) contain several success criteria that directly affect accessibility for people with reading and spelling disorders:
WCAG 1.4.8 – Visual Presentation (Level AAA): Text should be presented to maximize readability – with adequate line spacing (at least 1.5x), large font sizes, and no more than 80 characters per line.
WCAG 2.5.5 – Target Size (Level AAA): Interactive elements should be large enough to be easily activated – important for people whose motor control is impaired by the cognitive load of reading.
WCAG 3.1.5 – Reading Level (Level AAA): Text should be written at a reading level no higher than lower secondary education (i.e., use simple, clear language).
WCAG 3.3.5 – Help and Documentation (Level AAA): Help and documentation should be easy to find and understand, with clear, concise language.
These criteria are also legally binding in Germany via EN 301 549 and the Accessibility Strengthening Act (BFSG). With easyStatement, you can create a legally compliant accessibility statement that documents compliance with these criteria.
Checklist: Accessible Web Design for Dyslexia
Font and Typography: Use dyslexia-friendly fonts (OpenDyslexic, Dyslexie Font, Arial), font size at least 12-14px, line spacing at least 1.5x, word spacing adequate, letter spacing increased.
Layout and Structure: Use meaningful headings (H1-H6), short paragraphs (max 5-7 lines), lists instead of long running text, no more than 80 characters per line, generous margins.
Color and Contrast: Strong contrast with background (at least 4.5:1 for text), information not conveyed by color alone, limited color palette, no blinking or flashing content.
Content and Multimedia: Text-to-speech functionality, transcripts for audio and video, infographics to support text, alternative text and visual elements, PDF also available in HTML.
Navigation and Operation: Clear, consistent navigation, simple, logical menu structure, large, easy-to-use buttons and links, simple search functionality, speaking URLs and meaningful link labels.
Language Level: Use simple, clear language (middle school level), short sentences, active voice, avoid jargon, complex or confusing wording, explanation of difficult terms.
Tools and Resources for Testing and Optimization
Readability Analysis Tools: Tools like Flesch-Kincaid Readability or Readability-Score calculate your text reading age and help make them more understandable.
Font Testers: Online tools like the "Dyslexie Font Tester" or "Readable Font Tester" show how your website looks with different fonts for people with dyslexia.
Simulation of Visual Impairments: Extensions like "Accessibility Checker" or browser features can help identify contrast and readability issues.
Text-to-Speech Software: Tools like NVDA (free), JAWS, or browser-native readers help test the text-to-speech experience.
Automated Accessibility Testing: easyMonitoring from SiteCockpit offers automated checks of your entire website against WCAG standards – including checking readability, contrast, and structure that are essential for people with dyslexia.
Frequently Asked Questions About Dyslexia
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