Visual difficulties

Currently the BDA is working to update this information with Caroline Holden of the SpLD Assessment Standards Committee (SASC) and Dr Jim Gilchrist of the School of Optometry and Vision Science, University of Bradford.


Visual Stress

Visual stress is not a symptom of dyslexia but 50% of those who have visual stress also happen to be dyslexic.

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 (see contact details below). 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 help 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
  • 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.
  • Coloured filters for reading or for using with a computer screen can be extremely helpful in coping with visual stress. These are available from

An example of visual stress:

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Finding a specialist practitioner

You are advised to ensure that any practitioner is properly trained and qualified in this area.

Aston University (Birmingham) Optometry Department

Not-for-profit learning and vision clinic.
Tel: 0121 204 3900

Bradford University Optometry Eye Clinic

Free initial assessment for visual stress.
Tel: 01274 234649

British Association of Behavioral Optometrists (BABO)

Ask for your nearest accredited behavioural optometrist or see list online.

Dyslexia Research Trust (eye clinics in Reading and Oxford)

A leading research organisation into the visual aspects of dyslexia.
Tel: 0118 958 5950

The Institute of Optometry

Runs courses for teachers and eyecare practitioners and has a clinic for people with reading problems.
Tel: 020 7407 4183
Fax: 020 7403 8007

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.

University Optometry Departments

It would be worth contacting Optometry Departments of universities to see if they offer a service of assessments.

Society for Coloured Lens Providers

A list of recommended practitioners following an agreed code of conduct.

Visual Perception Unit, University of Essex

Information on Colour in the Treatment of Visual Stress, references to practitioners and suppliers.
Tel: 01206 872 381