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!