University of Edinburgh

The Role of Vision in Learning

Presented on Friday 7 November 2008

Visual Barriers to Reading

Nadia Northway

Types of conditions seen

  • Dyslexia
  • Developmental Co-ordination Disorder
  • Dyspraxia
  • Meares-Irlen Syndrome/Visual stress
  • Migraine
  • Brain Injury
  • Multiple Sclerosis
  • ME
  • Asperger's Syndrome/ Autistic Spectrum

All share one thing in common- problems reading!

The art of reading

  • Reading requires efficient processing of visual and auditory information
  • 80% of learning is done through the visual channel
  • Various stages of visual processing have been identified as weak or poorly functioning in poor readers
  • Vision Scientists have been aware of poor visual functioning and this has been widely reported since the 1950s.
  • The first paper published was by Coller in 1896.

Evolution of Man

  • Reading is not a survival skill
  • Why do 10% of our population find reading difficult to learn?
  • Neurophysiological disadvantage

Reading Facts

  • 5 million adults in UK are illiterate
  • 1 in 6 school leavers are unable to read and write
  • UN state that 7 million adults are functionally illiterate in UK
  • Functional literacy difficulties: person may be able to read but cannot read utility bills, newspaper articles etc
  • European Parliament have stated that 10-20% of union's population and up to 30% of EU candidates are unable to understand and use printed material necessary to function in society
  • Germany 14% Poland 42% Portugal 50%
  • Although literacy as a whole is lower in India than western countries, illiteracy exists in about 12% of those receiving tuition.

Right Equipment/ Right Ingredients

frying pan

Successful Cooking


Visual Aspects of Reading Difficulty

Refractive Aspects

  • Myopia - short sight – difficulty seeing far away
  • Hypermetropia - long sight - difficulty focussing for near and far

Mechanical aspects:

  • Eye alignment
  • Fine motor visual skills such as focusing and co-ordination
  • Eye movement difficulties( saccades and SP)
  • Tracking difficulties

Perceptual Aspects

  • Meares-Irlen syndrome/Visual stress
  • Visual perceptual problems: visual figure ground, visual sequential
    memory, visual closure, visual memory, visual spatial relationships,
    form constancy, spatial memory

How do vision and dyslexia relate?

  • Dyslexia cannot be diagnosed from assessment of vision
  • Dyslexia is not caused by visual problems alone
  • However problems with vision can contribute to learning difficulties by hindering passage of information to brain or by causing unpleasant symptoms
  • 40% of the brain is dedicated to visual input
  • 80% of learning done through vision

Research Findings

  • Post Mortem examination - Magnocellular cells, Corpus callosum- control temporal or timing
  • fMRI studies
  • Genetics: chromosome 1,2, 6,15 and 18
  • Monocular Occlusion
  • Eye movements
  • Attention – temporal control
  • Contrast Sensitivity, Motion detection

Smooth Processing

Letters arrive in the visual cortex but the timing is erratic and the ltteres dtno aivrre ni seuencqe.

Types of Dyslexia

Boder classification

  • Auditory= Dysphonetic
  • Visual = Dyseidetic
  • Mixed= Dysphonetic/eidetic
  • Fourth type Griffin 1992 Dysnemkinesiamotor difficulties combined with STM problems


  • Two channels for reading
  • Stages for reading
  • Orthographic
  • Phonological
  • Lexigraphical

The Many Strands that are Woven into Skilled Reading
(Scarborough, 2001)

Language Comprehension - Increasingly strategic

  • Background knowledge
  • Vocabulary knowledge
  • Language structures
  • Verbal reasoning
  • Literacy knowledge

Word Recognition - Increasingly automatic

  • Phon. awareness
  • Decoding (and spelling)
  • Sight recognition

Skilled Reading

Fluent execution and coordination of word recognition and text comprehension.

Reading is a multifaceted skill, gradually acquired over years of instruction and practice.

Three potential stumbling blocks to becoming a good reader

1. Difficulty learning to read words accurately and fluently.

2. Absence or loss of initial motivation to read, or failure to develop a mature appreciation of the rewards of reading.

3. Insufficient vocabulary, general knowledge, and reasoning skills to support comprehension of written language.

Vision and visual discomfort can affect reading by reducing accuracy and adversely affecting motivation because reading is uncomfortable, which in turn affects concentration. This in turn affects how much knowledge they acquire.