University of Edinburgh
 

Assessing Vision in Children with Additional Support Needs: Why and How?

Presented on Wednesday 31 October, 2012
J Margaret Woodhouse School of Optometry & Vision Sciences

Visual acuity and Contrast sensitivity

HOW do professionals assess vision?

Visual Acuity (detail vision)

Contrast sensitivity

Visual Acuity - letters

Visual Acuity - pictures

Visual acuity - preferential looking
Cardiff Test www.cardiffacuity.co.uk

Visual acuity - preferential looking
Teller Acuity Cards

Keeler Acuity Cards

Hiding Heidi

Contrast sensitivity - preferential looking

Cardiff Contrast test

What would make us suspect acuity or contrast problems?

Poor visual acuity

  • Getting close to objects
  • Inability to see detail at distance and/or near
  • Lack of interest in detailed tasks

Poor contrast sensitivity

  • Vision is variable (depending on contrast of task)
  • Inability to write on the line
  • More difficulty with pencil than pen

There is no reason why school staff can't use standard tests

  • Beware
    • A child learning the correct answer
    • A child peeping around a cover
    • A child losing interest
    • A child reluctant to guess
  • Know what is 'normal' for your test
  • Different tests give DIFFERENT results

Understand the visual problem

  • Know when performance will be affected.
  • Modify the environment.

Visual Acuity (VA)

Email from Ben's Mum - Ben is 6 years old and has Down's syndrome

Please send me some information that I can show to school.

I know what a difference this will make to Ben as one of his targets is to write on the lines which he couldn't do. It turned out the line was in pencil. I suggested that perhaps he couldn't see it, so his teacher then drew the lines in pen and instantly he could write on the lines!