Lens Dynamics, Inc.

MANDELL-MOORE BITORIC FITTING GUIDE

A. This is the method Lens Dynamics, Inc. uses to figure bitoric lenses.

B. We recommend bitorics when the corneal cylinder is 2.00 D. or greater.

C. Vertex powers after adding them together.

D. The most plus or least minus power goes with the flatter base curve.

E. Be sure to adjust power for the tear layer change.

F. We use Drum Readings to express our torics.

G. Fitting Philosophy:

Corneal Cylinder, D.    Flat Meridian         Steep Meridian

2.00 D.                 On K                  .50 D. Flatter

2.50 D.                 .25 D. Flatter        .50 Flatter

3.00 D.                 .25 D. "              .75 D.  "

3.50 D.                 .25 D. "              .75 D.  "

4.00 D.                 .25 D. "              1.00 D. "

5.00 D.                 .25 D. "              1.25 D. "

EXAMPLE: 44.00 / 47.25 @90 -3.50 -3.50 X 180

B.C. equals 37.75 / 46.50

Power equals -3.25 / -5.75 Vertex power before adjusting for tear layer change.

This calculator is intended for educational use. Free for distribution and copying to all educational institutions.