DiSanto HELP!

[puppydogeyes]

Hello! I am currently helping an employee study for her ABO. I recently just passed myself in May. I am trying to help her understand the Oblique cylinder chart but am having a horrible time explaining it. Can anyone help me???? Thank YOU!!

[lensgrinder]

Just remember that:

30 degrees away from axis is 25% of cylinder
45 degrees away from axis is 50% of cylinder
60 degrees away from axis is 75% of cylinder
90 degrees away from axis is 100% of cylinder

Step 1 Find the difference between your axis and the meridian that you are looking for
Step 2 Multiply the percentage from above times your cylinder power
Step 3 Add Step 2 number to your sphere.

Example: -2.00 -1.00 X 45 What is the power in the 90th meridian.

Step 1 90-45=45
Step 2 -1.00 X (0.50) = -0.50
Step 3 (-2.00) + (-0.50) = -2.50

Your total power in the 90th meridian is -2.50 D

Example: -2.00 +1.00 X 30 What is the power in the 180th meridian and the 90th meridian
Step 1 30-0 = 30 Note 0 and 180 are the same in this case
Step 2 +1.00 X (.25) = +0.25
Step 3 -2.00 + (0.25) = -1.75 @ 180

Step 1 90-30=60
Step 2 +1.00 X (0.75) = 0.75
Step 3 -2.00 + 0.75 = -1.25