What is visual dyslexia?

Each dyslexic is different and has different problems with language processing. In order to understand and manipulate language, a person needs co-ordination of hearing, sight, thinking and hand movement.

For some dyslexics, it is the visual input to the brain that is incorrect, and therefore it is difficult for the brain to make sense of text and the world in general.

Not all dyslexics have a problem with reading.

With visual dyslexia:

  • Letters or words may seem to be reversed
  • Text seems to move about the page and wobble around
  • Tracking from one line to another is difficult
  • Double vision is often present
  • Letters may disappear and reappear - a bit like a visual anagram
  • The eyes appear to dance around the page as fixing on one word is difficult
  • Word recognition is dependant on lighting, page background and type of text

In the visual dyslexic, these symptoms may be slight or severe, but it is not surprising that reading leads to symptoms of travel sickness and headaches!

Testing of visual symptoms of Dyslexia (visual stress)

Tests involve:

  • how well the two eyes work together (convergence, fixation disparity, stereopsis)
  • how the eyes track along lines when reading
  • the effects of coloured overlays on high contrast print
  • if specific tints are necessary on your glasses


The NHS does not pay for specific tests for visual stress, so extra fees are charged.

  • £45 for tracking and convergence exercises (includes two or three appointments)
  • £27.50 for coloured overlay tests including supply of an overlay
  • £40 for a test using the intuitive colorimeter for specific tints if overlays are still being voluntarily used after 6 months
  • £85 for the tint to be put on your lenses