University of Edinburgh
 

Functional Assessment of Vision

Presented 19-20 March 2008

Summary notes of  talk on MDVI assessment of functional vision

Alison Duthie

Children with Visual Impairment and Learning Difficulties.

What is the assessment for?

  • Aiding development
  • Aiding learning, by informing family, Teachers and Therapists

Assessment is therefore part of a system which supports the child and family (ref: Marianna Buultjens and and Stuart Aitken: "Vision for Doing").

Before the assessment:
Arrangements within the team: advance meetings allow time for the health and education members to look out notes on the child and share relevant information.

Phone calls to parents and school or family center to inform of the purpose of the assessment, their role in it, and to confirm that time and date are suitable.

Letters of confirmation to all. 

Notes looked out.

People present: class teacher/keyworker. Visiting VI teacher, Parent, VA Team: orthoptist, Staff Grade Paediatrician, Principal teacher, visual impairment

Visual Assessment Session

Setting Up: Where? Needs quiet and good light.
Doctor takes history or confirms. She often knows family already. Understands interplay of medications eg; drug to dry excess saliva can cause dry eyes. Understands brain lesions and medication effects on brain.

Doctor asks about

  • Medication and which doctors the child sees
  • Glasses
  • Registration
  • VIScotland
  • Recent visual behaviour

Information from teacher/keyworker/parent:

  • Optimum position for seeing
  • Optimum position for doing
  • Recent visual behaviour
  • Responses: smile? Vocalisation? Hand movement?

Importance of orthoptist:

  • Acuity
  • Degree of squint
  • Eye movements
  • Observation skills

Importance of teacher:

  • Understands type and stages of curriculum
  • Class situations in mainstream and special school
  • Idea of vision for communication, learning, mobility

Can discuss targets  and methods

Assessment of vision A
(refer to Assessment Tools below)
Dark room:  looking for awareness, then attention, also fields
Lights and torches, reflection, UV light and fluorescent cloths and wands,

Behaviour looked for: consistent response of any kind.

  • Fixing
  • Tracking

Combine sound and feel with light

Assessment of Vision B

Acuity:

  • Gratings
  • Black/white checked cloth
  • Mask
  • Wig
  • Choc drop and 100s and 1000s
  • Cardiff cards

Kay Pictures

Precision Vision charts

Single symbols and crowded symbols

Fixing and tracking: torches, small toys, finger puppets, Midge

Saccades: 2 toys as above

Contrast: Hiding Heidi
Precision Vision symbols

Fields: Pom pom and Stycar Ball

Pupils: observation

Nystagmus and OKN

Squint

Complexity: choc drop and 100s and 1000s on plain and pattern

Movement: gross: watch behaviour
finer: toy car, bubbles

3D: Wirt Fly Test

Facial expression: mum or teacher

Dark adaptation: Precision Vision tiles

General attention and fun:
Bright books, survival foil blanket, bells, musical toys, electric toothbrush.

Assessment Tools

Function

Suggested tools

Awareness of light

Dark room with ultraviolet light, fluorescent cloth, white gloves. Then red torch and white torch. Flashing/still

 

Blinds, fences and trees in sunlight

Attention to light  and pursuit

Dark room. Torches, fluorescent materials in UV light. Bells

Pupil dilation, nystagmus

Small torch with observation only

Squint

Prisms

Pursuit

Finger puppet, toy car, ball, bubbles, moving people

Sacchades

Finger puppet and small toys

Acuity: distance

Mask, tinsel wig, black/white checks. Kay Pictures. Precision Vision Symbols

Acuity: near

Lea Gratings, Cardiff Cards, 100s and 1000s, facial recognition/expression

Contrast

Precision Vision: Hiding Heidi or symbol contrast charts. Choc button on contrasting/non-contrasting cloths

Fields of vision: upper

Yellow and black spinning pom-pom

Fields: lower

Stycar ball on stick

Complexity

Choc button then 100s and 1000s on plain then patterned cloth

Crowding

Precision Vision Single symbols and crowded symbols

Movement

Observation, moving toys

Dark Adaptation

Precision Vision tiles

Colour Vision

Precision Vision  Colour Test