4.
Starting with box #1, ask the test subject to point to or identify
(top, bottom, left or right) the circle that appears to be floating
or different from the others
5.
Repeat last step for boxes 2-10
6.
When one is missed, retest the preceding box to ensure that
the test subject can achieve this level and was not just
guessing
Scoring
1.
Record the level of stereopsis for the circle in the last box
chosen correctly
2.
Refer to Answer Key on back of test booklet
Section C (For Children)
1.
In each line – A, B & C, only one shape appears to be floating
or forward from the others
2.
Taking each line in order, have test subject look at the
geometric shapes at bottom of page and point to or name the
shape on each line A, B & C that appears to be floating or that
is different from the others on that line. If one is missed, retest
the preceding line to ensure that the test subject can achieve
this level and was not just guessing
Scoring
SCORE
KEY
Seconds of arc
16 in., (40 cm)
Shepard
Percentage
Verhoff
Distance
A .
400
15%
0.1
B .
200
30%
0.2
C .
100
50%
0.3
CARE/HANDLING & STORAGE
Clean
vectographic
pages with a soft, damp lint-free cloth
wp
Store closed booklet in a cool, dry place away from direct
sunlight
Clean polarized viewers using lens cleaner and soft, lint free cloth
WARRANTY
1-year manufacturer warranty from date of purchase
C
P
M
Manufactured in USA by
Vision Assessment Corporation © 2018
Vision Assessment Corporation
2675 Coyle Avenue
Elk Grove Village, Illinois 60007 USA
Phone: 1 847 239 5889
Toll Free USA: 1 866 887 9692
Email:
Web:
www.VisionAssessment.com
The
Butterfly-S
Stereo Acuity Test
P/N 1010S
TECHNICAL MANUAL
MDSS GmbH,
Schiffgraben 41, Hannover 30175, Germany
