User's Manual

40 CDC-1 -----------------------------------------------------------------------------------------------------------------------------------
9.1. Cylinder Axis Test
Title
Content
Purpose
To determine the correcting astigmatic axis roughly.
Chart
Aux. Lens
None
Procedure
① Occlude one eye that’s not to be examined.
② Add spherical lens power as much as the patient can read numbers around the chart.
③ Ask the patient if any direction is seen thicker.
④ If all the directions are seen even, there is no astigmatism exists. Otherwise thickest
direction is astigmatic axis.
9.2. Cylinder Power Test
Title
Content
Purpose
To determine the correct cylinder power
Chart
Aux. Lens
None
Procedure
① Occlude one eye that’s not to be examined.
② Add cylinder power until the patient sees all the directions evenly.
③ 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.
9. Optometric Test Using the Acuity Tester