Fitting curve / Central base curve interaction

The lens is designed with two very distinct curves; the unusually flat CENTRAL BASE CURVE and the FITTING CURVE. The CENTRAL BASE CURVE serves as a smooth secondary refractive surface and is designed to closely match the central post surgical curvature of the cornea. The FITTING CURVE acts as support to the central base curve and with a unique reverse geometry design allows the mid-peripheral portion of the lens to align with the cornea outside the post surgical (treated) area, ensuring optimum centration.

Modifying the central base curve value only

By steepening (increasing clearance) or flattening (decreasing clearance) the central base curve, the tear layer profile is modified over the post surgical area only. If the fitting curve is kept constant, changing the central base curve will not alter the way the mid-peripheral area of the lens aligns with the cornea outside of the post surgical (treated) area. (see illustration #3).

Modifying the fitting curve value only

Since the fitting curve supports the central base curve, changing the fitting curve value, will modify the tear layer profile over the central post-surgical (treated) area as well as lens alignment in the mid-peripheral area (see illustration #4).