Haag-Streit VISUTRON 900 Touch, User Manual

Page: 53 / 88

Cross Cylinder
(continued)
Split Cyl Test
Note: Tap Test to switch the type of XCyl test (Manual/Smart/Split Cyl).
The Split Cyl Cross Cylinder test shows the patient two charts at the same time when adjusting Axis and
Cylinder.
Note: When the patient has Sphere power equal to or greater than -12.25 D or 7.75 D, the Split Cyl
test cannot be used.
1. Tap
XCyl
on the menu bar at the bottom of the main screen.
2. Tap Split Cyl to start the test.
If the current Cylinder value is zero, an Astigmatism check will automatically start, and a 0.50 D JCC lens
will be placed in the Phoroptor head. Refer to the Examination for Astigmatism section of this manual.
Note: Axis is freely adjustable by turning the CONTROL KNOB .
Note: The amount of Axis change can be selected by tapping the 1° , 5° , or 10° screen icon, located in
the lower left of the screen.
3. Ensure the patient can see the red and green edges of the Split Cylinder lens.
4. Ask the patient: “Which chart is clearer, the red or the green?”
5. Press the
RED
or the
GREEN
button, or tap
Red
or
Green
, based on the patient’s response.
6. Repeat steps 4 and 5, until the patient sees the two charts equally clear or equally blurry.
7. Press the CONTROL KNOB , press the ENTER button, or tap Equal , to save the Axis value.
Note: The amount of cylinder change can be selected by tapping the ±0.25 D , ±0.50 D , or ±1.00 D
screen icon, located in the lower left of the screen.
8. Ask the patient: “Which half is clearer, the red or the green?”
9. Press the RED or the GREEN button, or tap Red or Green , based on the patient’s response.
Note:
Cylinder is freely adjustable by turning the
CONTROL KNOB
.
10. Repeat steps 8 and 9, until the patient sees the two charts equally clear or equally blurry.
11. Press the CONTROL KNOB , press the ENTER button, or tap Equal , to save the Cylinder value.
This completes the Split Cyl Cross Cylinder test.
Performing an Exam
(continued)
53
16243-101 Rev. G