6
ADMINISTERING THE TEST
Section A
• Place the polarized viewers on the test subject
PLEASE NOTE
: IF TEST SUBJECT WEARS PRESCRIPTION GLASSES, THE POLARIZED
VIEWERS SHOULD BE WORN OVER GLASSES
• Before opening test booklet, familiarize test subject with 4 Lea Symbols® on front cover (House, Circle,
Square & Apple)
• The test subject should be able to correctly identify at least 3 of the 4 non-stereo, two-dimensional
symbols on the front cover before administering the test
• Open test booklet and fold so that only Page 1 can be viewed by test subject
• Hold the test approximately 16 inches (40 cm) from the test subject
• Beginning with Part A, ask the test subject to identify the symbols in each of the 4 boxes - 3 boxes
contain symbols and 1 box is blank
• Repeat last step for Parts B, C & D
• If test subject is unable to identify at least 1 symbol, turn to Page 2 and ask the test subject to identify
the “L” & “R”. If the patient is unable to perform this task, the patient is untestable
Scoring
Refer to Answer Key on back of test booklet
Section B (For Adults)
• Turn booklet so that only Page 2 can be viewed by test subject
• Ask test subject to look at the 12 boxes each containing 2 circles
• Only one circle in each box will appear to be floating or forward from the others
• Starting with box #1, ask the test subject to point to or identify (left, middle or right) the circle that appears
to be floating or different from the others
• Repeat last step for boxes 2-12
• When one is missed, retest the preceding box to ensure that the test subject can achieve this level
and was not just guessing
Scoring
Record the level of stereopsis for the circle in the last box chosen correctly
Refer to Answer Key on back of test booklet
Section C (For Children)
1. In each line – A, B & C, only one symbol appears to be floating or forward from the others
2. Taking each line in order, have test subject look at Lea Symbols® at bottom of page and point to or
name the symbol 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
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
ENGLISH
