Refraction
Keratometry

Lens Type
<
>
Calc Type
Soft Sphere
Soft Toric
GP Sphere
GP Bitoric
SPE / CPE
GP Back Toric
GP Front Toric
Instructions
Desired diameter:
Adjust base curve
Index of refraction
Some lens options:
Or, do a soft lens search
Searching
Lens power
Power
-
Vertexed refraction
Power
=
Uncorrected power
Power
Lens base curve
Power
-
Keratometry
Power
=
Tear lens power
Power
Lens Power
Power
+
Tear lens power
Power
=
Total corrected power
Power
Lens Power
Power
+
Induced Cylinder*
Power
=
Total corrected power
Power
Vertexed refraction
Power
-
Total corrected power
Power
=
Uncorrected power
Power
Compare this with another lens (for example, the patient's current lens)
Base Curve:
Power:  

Purpose: This tool allows you to calculate powers for a variety of contact lens options.

Instructions:

  1. Enter the power of your contact lens in the first box.
    • This can be done in plus or minus cyl:
      • eg) -10.00-3.00x90
      • eg) -13.00+3.00x180
  2. Enter your keratometry in the second box.
    • This can be done in either of these formats:
      • 43.00 / 45.00 @ 090
      • 43.00 @ 180 / 45.00 @ 090
  3. Choose the desired lens type in the third box