Visual Stress Test


Many children and adults suffer from visual discomfort when reading. Visual stress refers to reading difficulties, light sensitivity and headaches from exposure to disturbing visual patterns. This can affect reading fluency, concentration and comprehension and can cause rapid fatigue. It can also be responsible for print distortion such as the movement of print and rivers running through the print. The severity of these symptoms can vary from person to person and can occur despite normal vision.

Visual stress is also commonly known as “Meares-Irlen Syndrome” or “Scotopic Sensitivity Syndrome.” Approximately 5% of the population is severely affected by Visual Stress and 20% to a lesser degree. It is found to exist in many conditions including:

  • Dyslexia
  • Dyspraxia
  • Photosensitive Migraine
  • Photosensitive Epilepsy
  • Autism
  • ADHD
  • Head Injuries
  • Multiple Sclerosis


Try our simple Visual Dyslexia test below. Is the black and white text uncomfortable to read? You can change the colour of the background to find the most comfortable.


Theories from studies have indicated that Visual stress is due to a hyper excitability of the neurons in the visual cortex. This means that some of the cells in the part of the brain that deal with processing visual information work too fast and do not respond in the way they should.


Visual Stress is not Dyslexia but can be particularly prevalent in Dyslexic individuals. If Visual Stress is identified and colour is used to alleviative some of the symptoms, other learning difficulties such as Dyslexia can be easier to cope with.

There are a large percentage of children and indeed adults who are not identified as being Dyslexic but still suffer with these symptoms. The appropriate coloured overlay or Precision Tinted Lenses can also help this group of individuals.


  • Movement of print
  • Blurring of print
  • Letters changing shape or size
  • Letters fading or becoming darker
  • Patterns appearing, sometimes described as “worms” or “rivers” running through print
  • Illusions of colour (blobs of colour on the page or colours surrounding letters or words)
  • Rapid tiring
  • Headache or eyestrain
  • Moving closer to or away from the page
  • Becoming restless
  • Using finger as a marker
  • Skipping words and line
  • Rubbing eyes and blinking excessively
  • Low self esteem


At Dickens Eye Clinic we specialise in diagnosing and treating patients of all ages with Visual Stress. Our Senior Optometrist has over 15 years experience working with Visual Stress and we can carry out a specialist assessment which often leads to remarkable improvements in reading speed and attention span for the individual. This is attained via the use of coloured overlays, coloured glasses and contact lenses and even various eye exercises. The assessment usually lasts 60 minutes and we use technology known as an Intuitive Colorimeter to help select the ideal colour for the individual.

If you would to book in for a Visual Stress Test or would like any more information please call us on 0121 744 5544 or email us at:


The Intuitive Colorimeter developed by Professor Arnold Wilkins and the Medical Research Council is fully supported by research studies and peer review controlled trials. It is used under the directions of an Optometrist to logically and sequentially explore colour space to find the optimal Precision Tint for the relief of perceptual distortions in Visual Stress.

The instrument independently changes the 3 parameters of colour; hue, saturation and brightness while the eyes are colour adapted. This will give a final colour which is extremely precise to each individuals needs. The colour will be different for each individual and the Colorimeter has over 100,000 colour combinations. In its most effective form, this prescription will be delivered as Precision Tinted Lenses.

The optimal colour which will benefit each individual can change over time, especially with children. It is therefore very important that the patient visits us regularly for re-evaluations (usually every 12 months). The optimal colour can also be available with soft Contact Lenses.

Visual Stress



Overlays are coloured sheets of transparent plastic, which can be used for all reading tasks. The use of an overlay has been shown to enable an increase in reading fluency, efficiency and duration. Research also demonstrated that the colour selected would vary for each child.

Precision tinted lenses are recommended over the use of Coloured Overlays as they can provide a much more accurate and precise colour for each individual and will also be more convenient for board and computer work. Studies have shown that many individuals need a precise colour that can only be found with the Intuitive Colorimeter.

The colour chosen as an overlay may not be the same as that chosen by the Intuitive Colorimeter. It is therefore not recommended to offer lenses tinted to match the colour of the selected overlay. Lenses tinted in this way may offer very little benefit.