- Visual Stress.
- Finding a specialist practitioner.
- Computer aids for visual stress.
- Further reading.
People with visual stress may experience one or several of the following:
- Blurred letters or words which go out of focus.
- Letters which move or present with back to front appearance or shimmering or shaking.
- Headaches from reading.
- Words or letters which break into two and appear as double.
- Find it easier to read large, widely spaced print, than small and crowded.
- Difficulty with tracking across the page.
- Upset by glare on the page or oversensitive to bright lights.
In some cases any of these symptoms can significantly affect reading ability. It can also make reading very tiring. Of course a child will not necessarily recognise what they see as a problem, as this is how they always see text.
If a child complains of a least one of these problems or has difficulty at school, they should be referred to an optometrist or orthoptist with expertise in this particular field. Many dyslexic people are sensitive to the glare of white backgrounds on a page, white board or computer screen. This can make the reading of text much harder.
- The use of cream or pastel coloured backgrounds can mitigate this difficulty as can coloured filters either as an overlay or as tinted reading glasses. - People with reading difficulties sometimes have a weakness in eye co-ordination or focussing and an specialist practitioner might recommend treating this with eye exercises or glasses. If these problems are present, they should be detected and treated before coloured filters are prescribed.
- Research in the UK and in Australia shows that people who need coloured filters, who are said to have visual stress, need to have exactly the right colour. Many optometrists and orthoptists use a special instrument, the Intuitive Colorimeter, to determine the exact colour that is necessary for coloured glasses.
- The choice of colour of text on white backgrounds can also affect clarity e.g. using red on a whiteboard can render the text almost invisible for some dyslexic students. For information on dyslexia friendly text see Dyslexia Style Guide.
An exmaple of visual stress:
Finding a specialist practitioner.
You are advised to ensure that any practitioner is properly trained and qualified in this area.
Society for Coloured Lens Providers.
A list of recommended practitioners following an agreed code of conduct.
Local Dyslexia Associations.
Contact your Local Dyslexia Association for recommendations of suitable local practitioners.
Contact your GP for a referral to an appropriate specialist. In some hospitals the orthoptist may have expertise in this field.
Dyslexia Research Trust have Eye Clinics in Reading and Oxford.
Tel: 0118 958 5950
A leading research organisation into the visual aspects of dyslexia.
Visual Perception Unit, University of Essex.
Information on Colour in the Treatment of Visual Stress, references to practitioners and suppliers.
Tel: 01206 872 381
Bradford University Optometry Eye Clinic.
Free initial assessment for visual stress.
Tel: 01274 234649
Aston University (Birmingham) Optometry Depatrment.
Not for profit Learning and Vision Clinic.
Tel: 0121 204 3900
University Optometry Departments.
It would be worth contacting Optometry Departments of universities to see if they offer a service of assessments.
British Association of Behavioral Optometrists (BABO).
The Institute of Optometry.
Runs courses for teachers and eyecare practitioners about vision and reading difficulties and has a clinic for people with reading problems.
Tel: 020 7407 4183
Fax: 020 7403 8007
The BDA Shop stocks a range of coloured overlays, both multiple packs of different colours and individual colours.
Institute of Optometry Sales Ltd.
Supply the Wilkins Intuitive Overlays, The Wilkins Rate of Reading Tests and other items for teachers and eyecare professionals.
Tel: 020 7378 0330
Cerium Visual Technologies.
List of optometrists in UK who have a Wilkins Intuitive Colorimeter and can prescribe Precision Tinted. Also supplier of coloured overlays.
Tel: 01580 765 211
Fax: 01580 765 573
Cantor & Nissel.
ChromaGen Haploscopic lenses are a type of colour based system for spectacles or contact lenses.
Licensed practitioners round the UK.
Tel: 01280 702 002
The Irlen Centre. Tinted lenses.
Crossbow Education produce a pack of 10 inexpensive "Eye Level Reading Rulers", in the full range of colours recommended by leading vision scientists. Particularly helpful for focusing and tracking as well as combatting white glare.
Crossbow also produce coloured overlays in the same ten colours as the reading rulers, as well as tinted exercise books and pads, and the "virtual" reading ruler and overlay for use on the computer.
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.
Tel: 0845 269 7272
Fax: 0845 269 7373
- Monitor ovelays are available in different shades and sizes which are held onto the screen by static. Available from the BDA Shop.
- Claro View: software offering a simple way of changing the background colour of the screen, with a wide range of different colours.
- Claro Screen Ruler suite: software to help with visual tracking and focusing on-screen. The Screen Ruler allows part of the screen to be highlighted or underlined depending on the user's preference. It provides a strip or ruler across the screen, which can have the contrast changed and have the background coloured or greyed out.
Dyslexia and Vision. Bruce J.W. Evans. Wiley
Visual Factors in Reading. Edited by Piers Cornelisson & Chris Singleton. Wiley
Tel: 01243 843 294
Fax: 01243 843 303