User's Manual

--------------------------------------------------------------------------------------------------------------------- CDC-1 User Manual
41
9.3. Binocular Cylinder Axis Test
Title
Content
Purpose
To determine the correcting astigmatic axis roughly.
Chart
Aux. Lens
Polarized filter
Procedure
① Add spherical lens power as much as the patient can read numbers around the chart.
② Ask the patient if any direction is seen thicker.
③ If all the directions are seen even, there is no astigmatism exists. Otherwise thickest
direction to get astigmatic axis.
9.4. Binocular Cylinder Power Test
Title
Content
Purpose
To determine the correcting cylinder power
Chart
Aux. Lens
Polarized filter
Procedure
① Add cylinder power until the patient sees all the directions evenly.
② If the thickest direction changes by adding cylinder power, adjust the cylinder axis
together.
- Plus the axis if the thickest direction changes in clockwise.
- Minus the axis otherwise