University of Edinburgh

The Role of Vision in Learning

Presented on Friday 7 November 2008

General Advice and Conclusion

Nadia Northway

Eye Care Protocol

  • Correct binocular vision problems first
  • Children should have trial with overlay and reading should e measured with and without colour to show effect. Trial should last 12-16 weeks
  • Colour: If positive effect on reading speed and visual comfort then prescribe precision tinted lenses
  • Rarely use overlays in people over the age of 14
  • Treat motor visual problems and then visual perceptual problems.

Teacher Protocol

  • Request parents take child for routine test
  • Use Visual Stress Index
  • Ask for referral to Orthoptic Department if BV problems seem to exist
  • Try overlay with child
  • If positive response to overlay then coloured lenses should be prescribed- see local protocol
  • Change the ASL Act (2004)
  • Writing- consider vision as causal factor for poor writing not just motor control.

Coloured Lenses

  • Research has confirmed that some accuracy required in tinting lenses to maximise visual comfort
  • May be prescribed for reading only or general wear
  • Minimum tint required should be prescribed
  • Tint may not match overlay
  • Controversy caution

Significance of Visual Problems in Poor Readers

  • Greater impact
  • Diagnosis of orthoptic problems and visual stress of paramount importance because:
  • High risk group
  • Less tolerance for visual disturbance due to greater cognitive demands with poor readers
  • Fatigue effects - poor readers will take longer to carry out work so visual skills need to be adequate
  • Two or three barriers to reading instead of one

Observations and Causes

More to improving reading than just using a coloured overlay - Any of the symptoms on the left may be caused by any of the causes on the right

Fatigue Poor convergence, jump convergence
Headaches Strabismus or poor binocular vision
Double vision Poor accommodation amplitude
Blurring of print Scanning/Tracking problems
Movement of print Meares-Irlen syndrome/Visual stress
Restlessness Saccadic eye movement problems
Missing words and lines Attentional problems
Head Movement Motor skills problems such as DCD/
Sensory Integration Dysfunction
Letter/ word reversals Poor visual perception
Losing the place  
Word/Letter substitution  
Poorly spaced hand writing  
Poor hand writing formation  
Organisational difficulties  


  • Poor readers may have motor and perceptual problems with vision which affect literacy.
  • Improving vision can aid literacy but problems not assessed in detail in routine eye test specialised testing required.
  • Differential diagnosis of BV and Visual stress.
  • Improving vision can improve accuracy, fluency and ultimately comprehension of reading.