Visual Stress

Visual Stress, also known as Meares-Irlen Syndrome, is a visual processing disorder that affects approximately 14% of the population. It is especially prevalent among individuals with reading and learning difficulties, dyslexia, ADHD, discipline problems, headaches, migraines, autism, and those who have experienced a traumatic brain injury.

The condition manifests itself differently in each individual and so is not currently identified by standardized educational, psychological, optometric, or medical tests.

Visual Stress in Action

Signs of Visual Stress

Light Sensitivity

Bothered by glare, fluorescent lights, bright lights, sunlight and sometimes lights at night

Some individuals experience physical symptoms and feel tired, sleepy, dizzy, anxious, or irritable. Others experience headaches, mood changes, restlessness or have difficulty staying focused, especially with bright or fluorescent lights.

Reading Problems

Poor comprehension

Misreads words

Problems tracking from line to line

Reads in dim light

Skips words or lines

Reads slowly or hesitantly

Takes breaks

Loses place

Avoids reading

Discomfort

Strain and fatigue

Tired or sleepy

Headaches or nausea

Fidgety or restless

Eyes that hurt or become watery

Attention and Concentration Problems

Problems with concentration when reading and doing academic tasks

Often people can appear to have other conditions, such as attention deficit disorder, and are given medication unnecessarily.

Writing Problems

Trouble copying

Unequal spacing

Unequal letter size

Writing up or downhill

Inconsistent spelling

Depth Perception

Clumsiness

Difficulty catching balls

Difficulty judging distances

Additional caution necessary while driving

Distortions

Words on the page lack clarity or stability; i.e., may appear to be blurry, moving, or disappear

Dyslexia and Visual Stress

“Dyslexia is a learning difficulty that primarily affects the skills involved in accurate and fluent word reading and spelling. Characteristic features of dyslexia are difficulties in phonological awareness, verbal memory and verbal processing speed. Dyslexia occurs across the range of intellectual abilities. It is best thought of as a continuum, not a distinct category, and there are no clear cut-off points.”
British Dyslexia Association – 2010

Dyslexia is primarily understood as a phonological deficit, meaning the brain struggles to process and organize sounds and speech patterns. Since dyslexia is a neurological condition rather than a visual one, it typically does not respond to visual treatments.

Diagnosis of dyslexia is carried out by certified specialist teachers, assessors, or educational psychologists—optometrists cannot diagnose dyslexia.

The most effective treatment for dyslexia involves specialist teaching, which is developed by a multidisciplinary team, including specialist teachers and educational psychologists.

However, some individuals with dyslexia also experience co-occurring visual issues, such as visual stress. In these cases, optometrists can play a role in managing the visual aspects of their condition.

Colorimetry and Visual Stress

Colorimetry involves using coloured overlays and tinted lenses to reduce or eliminate visual processing errors by filtering specific light wavelengths. The idea is that by lowering the sensory load, the brain can process visual information more efficiently.

The use of coloured filters to treat visual stress is somewhat controversial, as the evidence supporting it is mixed.

In our experience, some patients experience significant improvement with colorimetry, while others see little to no benefit.

If no benefit is observed, coloured filters will not be prescribed.