The Link Between Visual Difficulties and Dyslexia: What We Know So Far

Dyslexia is often described as a reading disorder linked to language processing and phonological skills. But for many children and adults with dyslexia, visual difficulties also play a significant role in their reading challenges. Visual difficulties don't cause dyslexia, but they can add to its symptoms, making reading even harder. Here, we’ll dive into the latest UK-based research on the link between dyslexia and visual processing and discuss the essential visual skills needed for smooth, effective reading.

At Learning DNA we regularly see children who appear to have dyslexic traits, but during our 360 degree assessment, we learn they are demonstrating visual difficulties that need further investigation.

Dyslexia’s Many Layers

Dyslexia is typically thought of as a problem with processing sounds in language. While it’s true that many people with dyslexia have trouble with phonemic awareness (hearing and identifying the small sounds in words), this doesn’t fully explain all of their reading struggles. Many individuals with dyslexia also experience issues related to how they process visual information, which can make letters appear blurry, seem to “jump,” or get jumbled up on the page.

For about 30-40% of individuals with dyslexia, visual processing issues are part of the picture. In fact, according to the British Dyslexia Association (BDA), these visual difficulties might affect their reading fluency, causing fatigue or headaches after short periods of reading.

What Visual Skills Are Essential for Reading?

Beyond just “20/20” vision, there are several crucial visual skills that all children need to read comfortably and accurately. When any of these skills is lacking, it can make reading tough or even uncomfortable. Here are some of the key skills:

• Eye Movement Control: Moving both eyes smoothly together to follow a line of text.

• Eye Focusing: Quickly focusing on objects near and far, which helps when switching between text and other visual information.

• Eye Teaming or Alignment: Coordinating both eyes to work together. Poor teaming can lead to double vision or blurry text.

• Central Vision or Visual Acuity: Also known as “sharp vision” or “20/20 vision,” essential for reading small text.

• Peripheral Vision: Being able to see side information while focusing on the text, which helps with tracking words and sentences.

• Depth Awareness: Recognizing how close or far an object is, helping to focus and comprehend text smoothly.

• Colour Perception: Differentiating between colours, which helps with letter and word recognition, especially in diagrams or illustrations.

• Visual Perception: Making sense of what the eyes see, like decoding letters and identifying patterns in words.

• Memory: Both short-term memory (remembering what’s just been read) and long-term memory (storing it) play roles in comprehension and fluency.

Struggles in any of these areas can make reading uncomfortable or slow. For example, poor eye movement control might cause a reader to skip lines, while issues with visual perception could make similar-looking letters, like “b” and “d,” confusing.

What UK-Based Research Says About Visual Issues in Dyslexia

1. Magnocellular Pathway Differences

• UK researchers have extensively studied the magnocellular pathway, which is responsible for quick processing of visual information and helps with eye movements and focusing. For people with dyslexia, the magnocellular system often doesn’t process motion as quickly, making it difficult to track words on a page. Professor John Stein from the University of Oxford has studied this connection for years, finding that around 75% of dyslexic people show issues in this visual system, contributing to their reading challenges (Stein, 2019).

• In particular, children with dyslexia and magnocellular deficits might struggle with tracking text as they read, often skipping lines or experiencing fatigue sooner than their peers.

2. Visual Crowding Effects

• “Visual crowding” refers to the difficulty in distinguishing individual letters or words when they’re surrounded by other letters, which is common in printed text. For children with dyslexia, crowding can make reading feel more exhausting or confusing. Dr. Julie Van Herpe, a vision scientist at the University of Manchester, has studied how this effect disproportionately impacts dyslexic readers and suggests that simple changes, like increasing letter spacing, can make reading less stressful (Van Herpe, 2022).

3. Binocular Instability and Eye Teaming

• Research from the University of Birmingham has shown that dyslexic readers are more likely to have “binocular instability,” meaning their eyes struggle to work together consistently. This instability can cause double vision or blurred text, leading to a phenomenon called “visual stress.” According to a 2021 study by Dr. Christopher Wilkins, treating this instability through eye exercises or using coloured overlays can significantly reduce visual stress and make reading more manageable (Wilkins, 2021).

Supporting Reading Skills Through Visual Interventions

Although visual issues don’t cause dyslexia, addressing them can make a big difference for some individuals. Vision therapy and exercises, for example, can help improve eye movement, focus, and teaming. In the UK, some optometrists and eye clinics offer specialized support for children with reading difficulties, which may include exercises to strengthen visual skills. Colour overlays or tinted lenses are also popular tools for individuals who experience visual stress, as they can reduce the effects of visual crowding and increase reading comfort.

Understanding the various visual skills required for reading gives a more comprehensive view of what might be affecting some dyslexic readers. By considering each child’s unique visual needs, educators and parents can create supportive environments and help kids with dyslexia reach their full reading potential.

If you have found this article interesting, then you are just scratching the surface of the work we regularly do at Learning DNA. We offer a free 15 minute telephone call in the first instance, so you can learn about what we do and how we may be able to help your child. We are in the business of improving learning outcomes for children, so give us a call and see how we can help! T: 0121 314 0703