PDR-7000 Operation Manual
4.4 Spherical Refinement
4.4.1 Red-green test
Chart: Red-green
Ideal appearance: The sharpness of the letters on the
red
and green sides appears equal.
[Procedure example]
1. Press or to occlude either measuring
window.
2. Present the red-green chart.
Press the red-green chart The PDR-7000 goes into SPH mode.
3. Fog the vision.
Turn the dial counterclockwise by increments of two to add SPH + 0.50 D.
4. Reduce fogging gradually until the sharpness of the letters on the red and
green sides appears equal.
Turn the dial clockwise.
The letters on the red side are sharper. → Turn the dial clockwise.
The letters on the green side are sharper. → Turn the dial counterclockwise.
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