top of page



young man suffering from visual stress


Visual stress (or Meares-Irlen Syndrome) is a condition specifically related to eye-strain, difficulties with reading and associated headaches and affects both adults and children. It is not dyslexia, which is a linguistic problem and is a general term for disorders involving difficulties in learning to read or interpret letters, words.

Visual stress is related to light sensitivity and can cause distortions such as blurred print, movement of letters or words, and the apparent appearance of patterns within a paragraph of text. These can affect people who are competent readers. Visual stress is thought to be caused by an over-sensitivity of the brain when presented with different patterns (‘visually induced cortical hyperexcitability’).


Such Visual Stress can be responsible for fatigue when reading. Problems with sight do not cause dyslexia. However, when dyslexia and visual stress co-exist, they exacerbate reading difficulties. Visual stress can be a trigger for migraines.

Filters, known as ‘coloured overlays’ can help children with visual stress to improve their reading skills. The individual-specific colour and type of overlay is determined by our qualified Optometrists.

visual stress

The following descriptions and symptoms are often found in those who live with visual stress:

  • Movement or blurring of print

  • Doubling or fading letters 

  • Eye strain

  • Illusions of colour within the test

  • Rapid fatigue and eye rubbing 

  • Patterns within the text like rivers

  • Glare and the page appearing "too bright"

  • Skipping words or lines​

Before presenting for a coloured overlays assessment it is required that all patients have had a full recent eye examination. 

bottom of page