Current definitions of dyslexia, based on the most recent research, state that the primary symptom in dyslexia is associated with phonological difficulties originating within spoken language processes, and not with visual difficulties.
However, some dyslexic individuals describe the following symptoms of visual disturbances:
- blurred print
- moving print
- double vision
- losing place in text
- omitting words or lines of text
- re-reading lines of text
- sensitivity to glare from white paper
- distortion of letters and shapes
- difficulty seeing black or red print on white background
- eyes watering, itching or burning with sustained focus
- eye strain
- difficulty maintaining concentration
- headache, fatigue and aversion to reading
If a child persistently experiences visual stress, it is advisable that they are referred to an optometrist or orthoptist for specialist examination. Eye exercises or glasses may be prescribed to correct any visual problems identified.
Many dyslexics experiencing visual processing difficulties and/or visual stress find coloured overlays helpful for a more comfortable reading experience. These can be purchased inexpensively from stationers or online suppliers [see below]. It is important to try out a range of colours to determine the most effective for an individual. A more expensive option is to purchase tinted reading glasses from a licensed practitioner [see below].
Where to go for a specialist eye assessment and overlays
You are strongly advised to ensure that any practitioner is properly trained and qualified in this area.
Contact your GP for a referral to an appropriate specialist. In some hospitals the orthoptist may have expertise in this field.
Cantor & Nissel Ltd
Tel: 01280 702 002
ChromaGen™ is a unique system of coloured lenses of a specific density and hue that are worn as either contact lenses or spectacles. For people suffering from colour deficiency or ‘colour blindness’, ChromaGen™ haploscopic filters work by changing the wavelength of each colour going into one or both eyes, which enhances colour perception and colour discrimination.
Further information can be found here.
Licensed practitioner for ChromaGen™ in Lincolnshire:
Mr P J S Enderby
Enderbys of Boston
84 Wide Bargate
Tel: 01205 311181
Cerium Visual Technologies holds the licence to manufacture and market the Wilkins Intuitive Colorimeter by The Medical Research Council. In addition to useful background information, their website provides a list of optometrists in UK who have a Wilkins Intuitive Colorimeter and can prescribe coloured lenses.
Specialist practitioner in Lincolnshire:
Paul Todd Opticians
2 Bunkers Hill
Tel: 01522 522088
Irlen Syndrome is a condition that affects the quality of life for 12-15% of the population but that is easily controlled through assessment and coloured filters that help children and adults regain control of their lives.
The website provides information about Irlen Syndrome, what types of symptoms are linked to Irlen Syndrome, and what treatments are available.
Licensed practitioner in the Midlands:
2 Grindleford Close
Tel: 01536 761597
Crossbow provide a Visual Stress Assessment Pack. The pack is written and designed for ease of use by non-specialists, and includes everything necessary to carry out a thorough assessment.
Crossbow also sell an inexpensive pack of six colour tinted reading rulers. These are helpful for focusing and tracking as well as minimising white glare.
The Institute of Optometry Sales supplies Wilkins Intuitive Overlays, Rate of Reading Tests, Testing Packs and other items for teachers and eyecare professionals [please note that they are unable to supply parents directly].
British Dyslexia Association Shop
The BDA Shop stocks a range of coloured overlays, both multiple packs of different colours and individual colours.
- ‘Dyslexia & Vision’ by Bruce Evans [Dyslexia Series (Whurr)]
Publisher: Wiley-Blackwell 
- ‘Reading Through Colour: How Coloured Filters Can Reduce Reading Difficulty, Eye Strain and Headaches’ by Arnold Wilkins
Publisher: Wiley-Blackwell 
- ‘Reading by the Colors: Overcoming Dyslexia and Other Reading Disabilities Through the Irlen Method’ by Helen Irlen
Publisher: Perigree Books [US] [revised edition, 2005]