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 |