U
U
n
n
i
i
c
c
o
o
s
s
D
D
i
i
g
g
i
i
t
t
a
a
l
l
R
R
e
e
f
f
r
r
a
a
c
c
t
t
o
o
r
r
10.5 Negative Relative Convergence
Purpose: In subjective test, process Negative Relative Convergence test.
Chart: Near Vision Chart
Auxiliary Lens: None
Target: Calculate the value of BLUR, BREAK, and RECOVERY.
Way of Test
1. On touch screen, press [FAR] to choose FAR Vision Mode or NEAR Vision Mode.
2. On touch screen, press [X∆] and [NRC] to process test.
3. In case of Far Vision Mode, Horizontal Von Graefe Chart is spread out on the screen
automatically. In case of Near Vision Mode, drop the Near Vision Van Graefe Chart at a
place of about 40cm, so that the patient would see it.
4. Turn the dial counterclockwise. When the chart is beginning to be blurred,
choose (BREAK) on the touch screen.
5. Turn the dial counterclockwise. When the chart is beginning to
be separated as two, choose (RECOVERY) on the touch screen.
6. Turn the dial clockwise. When the charts are united as one, press
(OK) button to conclude the test.
[Figure 10-5] Negative Relative Convergence