What is visual stress?

Lines of text are somewhat like a striped pattern.

What is visual stress?

Lines of text are somewhat like a striped pattern.

When some people look at black and white stripes of specific width and spacing, it causes visual distortions and illusions. These distortions are due to hyper-excitability in the part of the brain known as the visual cortex. It is thought that when some people try to read, the ‘stripy’ effect of the lines of print causes similar disturbances in the vision when reading.

This is known as Visual Stress, or Meares-Irlen Syndrome, or Scotopic Sensitivity Syndrome.

It affects approximately 20% of the population, and 5% are severely affected. This can affect reading fluency, concentration and comprehension, and it can cause eye strain/fatigue.

Visual stress is NOT dyslexia, but it can be particularly prevalent in dyslexic individuals.

Symptoms of visual stress are not always immediately obvious. Many individuals who suffer from this condition believe the discomfort they feel when reading or the distortions they experience on the page are “normal” and experienced by everyone.

Signs of Visual Stress

  • moving closer to or away from the page
  • becoming restless
  • using a finger as a marker
  • skipping words and lines
  • rubbing the eyes and blinking excessively
  • low self-esteem

  • 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

Who can visual stress affect?

Visual stress has been found to present alongside many conditions including the following:

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

How can visual stress be alleviated?

Colour has been found to be hugely beneficial in alleviating the symptoms caused by visual stress. The research carried out by Clinical Psychologist Professor Arnold Wilkins of the University of Essex and the Medical Research Council has confirmed this. Colour can be used in the form of coloured overlays or ‘precision tinted lenses’.

A process called ‘Colorimeter’ measures three different parameters of colour: hue, saturation and brightness. The precise tint required to alleviate visual stress can be determined by independently changing each parameter. These details can then be sent to a specialist laboratory to produce customised precision tinted lenses, which can be incorporated into a pair of spectacles.

Dyslexia and visual stress

Dyslexia is a term used to describe various specific learning difficulties that affect learning to read and spell correctly. Visual stress is NOT dyslexia, but it can be particularly prevalent in dyslexic individuals.
Many people with dyslexia may also suffer from visual stress and can, therefore, be helped by colour. Equally, a large percentage of children and adults are not identified as being dyslexic but still suffer from these symptoms. The appropriate coloured overlay or precision tinted lenses can also help this group of individuals.

What are coloured overlays?

Sheets of transparent coloured plastic can be placed over the text and used as a screening tool to determine if the colour will benefit the patient. They can alleviate some of the visual stress, making reading more comfortable. Each child will benefit from a different colour. The Wilkins Rate of Reading Test can be carried out to assess the benefit of the chosen coloured overlay.

How do you know if overlays are helpful?

If the child continues to use the overlay through choice or the teacher/parent reports an improvement, it has most likely been beneficial. The overlay is usually used for a trial period of approximately 6 weeks. Spectacles with precision tinted lenses can then be prescribed following a Colorimetry assessment. These are more convenient and versatile, as they can be used with whiteboards and computer screens. Moreover, the precision tinted lens is more accurate than the overlay, as many more colour combinations are used, and the tint will vary from person to person. The colour of the lens may differ from that of the overlay that was used initially.

The simple application of an overlay at an early stage could save years of anxiety and prevent the downward slide in confidence which occurs in most cases where children struggle to read. Therefore, overlays must not be reserved only for pupils who have been “statemented” or identified as requiring specific help. They should be available to any child who does not find reading comfortable.

Can adults be affected?

As we get older, visual stress can be less pronounced but still present. In many cases, the condition goes undiagnosed and untreated until adult life. If you suffer from migraines, multiple sclerosis, or a brain injury, you may benefit from precision tinted lenses too.

Suffering from visual stress or dyslexia is no barrier to excelling in all aspects of life. Famous people who have or had dyslexia include Tom Cruise, Orlando Bloom, Cher, John Lennon, Leonardo da Vinci, Winston Churchill, Richard Branson and Albert Einstein.