1. Functional Vision Assessment
Duncan McGregor
July 2015

2. Functional Vision Assessment
A functional vision assessment examines how a student who is visually impaired uses his or her vision in day-to-day activities in school, home and community.
Twofold purpose:
- to determine what the student sees
- to identify what helps or hinders the student’s visual performance (Anthony, 2000) (accommodations, ECC goals)

3. Whose job is it anyway?
A teacher of students who are visually impaired can:
Determine how a student who is visually impaired uses his or her vision in real-life activities.
Recommend accommodations or adaptations to - the educational environment - educational materials - teaching methods - etc.
Recommend programming in ECC areas
Determine eligibility for TVI service

4. Where do we start? Preparation for assessment
Review the file, esp. medical eye reports
Interviews/questionnaires for teachers, parents
Classroom observation (sample checklists)

5. Interpreting an eye report
Eye report forms:
Looking to Learn, p
YRDSB form
Sometimes doctor will provide written report and/or clinical notes

6. Guiding questions when interpreting eye report
Diagnosis, symptoms (nystagmus)? Implications
Stable/progressive?
Additional disabilities?
Acuity?
Distance vs. near vision?
Visual fields?
Glasses? For near or distance? Do they help?
Colour vision?
Lighting?
What materials will I bring to assess?
Looking to Learn, p. 26

7. Eye reports: What the doctor tells us
Acuity measures:
Distance: - Snellen notation (20/, 6/, etc.) - LogMAR (Log Minimum Angle of Resolution)
Near: - Snellen equivalents - M size (distance in metres at which LC letter subtends 5° of arc) - Jaeger - point size

8. LogMAR Notation
LogMAR eye charts have the same number of characters per line and same relative spacing.
Snellen
Angle
LogMAR
20/200
10°
1.00
20/160 8°
0.90
20/100 5°
0.70
20/80 4°
0.60
20/40 2°
0.30
20/20 1°
0.00

9. Near Acuity Equivalents* from Looking to Learn, p. 20
M size
Snellen equivalent
Jaeger
Point size (Lower Case)
0.4
20/20 or 6/6 3
0.5
20/25 or 6/8
J1-J2 4
0.8
20/40 or 6/12
J4-J5 6
1.0
20/50 or 6/15 J6 8
1.2
20/60 or 6/18 J8 10
1.6
20/80 or 6/24
J9-J11 14
2.0
20/100 or 6/30
J11-J12 18
4.0
20/200 or 6/60
J17 36
5.0
20/250 or 6/80
J18
10.0
20/500 or 6/150
J19
20.0
20/100sss0 or 6/300

12. Components of a Functional vision assessment
VISUAL CAPACITIES
Visual acuity - distance - near
Visual fields - peripheral - upper and lower - (central)

13. Components of a Functional vision assessment
Motility - alignment - tracking vertical horizontal diagonal crossing midline - scanning - convergence - nystagmus
Light and colour perception - colour vision - contrast sensitivity - light sensitivity - light/dark adaptation

14. Conducting the assessment
blink reflex
pupillary response
muscle balance
cover/uncover
eye preference
tracking
convergence
scanning
peripheral fields (confrontation field test)
then look at distance and near-point acuities

15. Colour and contrast sensitivity
Colour vision testing (Waggoner video) - Farnsworth - Ishihara - Color Vision Testing Made Easy
Contrast sensitivity testing - flip charts: Lea numbers, Lea symbols - Hiding Heidi