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“True” Aspheric Curves & Optics
• Highest Resolution Optics
• Crisp Distance and Near Vision

Aspheric and Multifocal Fitting Theory
If all corneas are aspheric, why are spherical lenses fit on aspheric corneas? The only way to equal the quality of optics that the natural lens of the eye produces is to match the aspheric shape of the eye with the lens. The eccentricity value is used to adjust the aspheric value of the lens to match that of the cornea. Aspheric and multifocal lens designs fit looser than spherical lens designs because the eccentricity value creates an elliptical shape within the central optic zone. The higher the eccentricity value, the quicker the radius flattens, and the steeper the base curve will need to be fit. The eccentricity value also produces the ADD Power in aspheric and multifocal lenses. Though the base curve needs to be fit steeper than the central cornea, the overall shape of the lens matches the overall shape of the cornea when fit correctly.

Two Zone Aspherics Ecc. Add Approximate Fit
Aspheric-15 (formerly K-10) .5e +0.25 0.75 - 1.00 steeper
Aspheric-16 .6e +0.50 1.00 - 1.25 steeper
Aspheric-17 .7e +0.75 1.25 - 1.50 steeper
Aspheric-18 (reduces WTR cyl.) .8e +1.25 1.50 - 2.00 steeper
Aspheric-20 1.0e +2.00 2.50 - 4.00 steeper

Three Zone Multi-Focals Ecc. Add Approximate Fit
Multifocal-19™ (Our #1 Multifocal) 1.0e +1.75 2.50 - 3.50 steeper
Multifocal-23 .1.3e +2.50 3.00 - 5.00 steeper

Front Aspherics Ecc. Add Approximate Fit
Aspheric-96 e-.6 +1.75 on flat CK

Back/Front Aspherics Ecc. Add Approximate Fit
Aspheric-17e-.6 .7e/e-.6 +2.00 1.25 - 1.50 steeper
Aspheric-18e-.5 .8e/e-.5 +2.00 1.50 - 2.00 steeper
Aspheric-19™e-.5 1.0e/e-.5 +2.25 2.50 - 3.50 steeper

Front Aspherics: By adding an e-.5 or e-.6 to the front surface of any aspheric or
multifocal lens design, the ADD power is increased by +.50 to +.75. By adding an e+.5 or
e+.6 to any aspheric lens design the ADD power is reduced.

Example: By ordering a MF-19™ e-.6, the ADD power is increased from +1.75 to +2.50.

Diameters: Aspheric designs are available from 8.0 to 12.2mm and multifocal designs available from 9.2 to 12.2mm.

For further fitting details download the “True” Aspheric Quick Fit Guide. Download PDF

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