Colorimetry: tints for visual stress
Several of our Optometristshave a specialist interest in the assessment and treatment of visual stress for both children and adults with reading difficulties. Visual stress (previously referred to as Meares-Irlen Syndrome) is a condition referring to reading difficulties, light sensitivity, strain, and headaches from exposure to disturbing visual patterns such as text on a page. Visual stress is thought to be caused by an over-sensitivity of the brain when viewing high contrast patterns, hence it has also been termed ‘pattern-related visual stress’. It can be responsible for rapid fatigue when reading and can affect both adults and children.
The following descriptions and symptoms are often given by individuals with visual stress to describe the discomfort they experience from everyday tasks such as reading:
- Movement of print.
- Blurring of print.
- Doubling or fading of letters.
- Illusions of colour within the text.
- Patterns appearing (sometimes described as “worms” or “rivers”).
- Glare and the page appearing “too bright”.
- Skipping words or lines.
- Using finger following.
- Rapid fatigue and eye rubbing.
The symptoms of visual stress can, for some people, be alleviated using precision colour-tinted spectacle lenses and coloured overlays. The colour needed to alleviate the symptoms is individual-specific and is determined by our accredited Optometrists using the Intuitive Colorimeter.
Clinical research in this area is ongoing and, at present, the scientific literature provides a divided picture. Despite the lack of settled consensus on the topic, many of our patients find their precision tinted spectacles and/or coloured overlays invaluable at alleviating their symptoms and return over the years for repeat orders.
Relief from Visual Stress - Coloured Overlay Assessment and Colorimetry
Step 1 – A Thorough Eye Examination
In the first instance we recommend that people with reading difficulties have a thorough Eye Examination to rule out an alternative cause(s) of the symptoms experienced. Specific emphasis will be given to assessing how well the eyes work together. In some cases, a need for spectacles or the prescribing of eye exercises is enough to alleviate the visual discomfort.
Step 2 – Coloured Overlay Assessment
Coloured plastic sheets are presented over text to assess for a reduction in the symptoms of visual stress. Through a process of elimination, the best colour is determined. Reading speed and accuracy is measured using the Wilkin’s Rate of Reading test both with and without the chosen overlay (or combination of overlays). If there is a significant improvement in reading speed and accuracy a coloured overlay is recommended. At this point the chosen overlay is taken away for use in home and school. In the case of children, we ask parents and teachers to monitor the child’s reading speed, comprehension and how frequently the overlay is used without being reminded. In most instances the overlay assessment and subsequent overlay home trial is used to ascertain whether an individual will benefit from precision colour-tinted spectacle lenses.
Step 3 – Colorimetry and the prescribing of tinted spectacles
Following a positive result from the overlay assessment and home trial we recommend a Colorimetry Assessment, following which tinted spectacles can be prescribed. The Intuitive Colorimeter is a specialist instrument that allows text to be viewed under different coloured light sources. The hue (colour), saturation (density of colour) and brightness are altered in tiny increments until the precise shade is found that best minimises or eliminates the patient’s symptoms. Tinted spectacles allow the colour to be accurately specified to the individual's needs and so are more effective than coloured overlays. Tinted spectacles are also more convenient to use than the overlay and can also be used when viewing other sources such as white boards and computer screens.
For more information or to book an appointment for an Eye Examination with Coloured Overlay Assessment or Colorimetry Appointment please contact us and speak to a member of our team.
Visual Stress and Dyslexia
Although the evidence is inconclusive, a 2016 study suggests that visual stress is a co-occurring factor in approximately 20% of those with dyslexia. We recommend all those with reading difficulties have a thorough eye examination to assess for common eye focusing or eye coordination abnormalities that may be the cause of their symptoms prior to investigating the effectiveness of colour.
Visual Stress, Migraine, and other conditions
There are many triggers for migraine such as stress, certain foods, or hormonal factors. For some people everyday patterns such as text can trigger a migraine without necessarily causing difficulties reading. For these people the use of precision colour-tinted lenses can help reduce the frequency of these visually precipitated attacks. There is also research that suggests these coloured lenses can help those who suffer with photosensitive epilepsy, autism, ADHD, and multiple sclerosis.
What is Colorimetry?
Society for Coloured Lens Providers
Our accredited Optometrists are members of the Society of Coloured Lens Prescribers and abide by their code of conduct when providing eye care and treatment for those with visual stress
For more information visit:
- Society of Coloured Lens Prescribers
- Dyslexia Association of Bexley, Bromley, Greenwich and Lewisham
- Cerium Visual Technologies
- British Dyslexia Association
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