Traditional Front Side Progressive
When the progressive design was on the front, there was a “varying” base curve “built in”– a higher base curve in the reading area vs. in the distance area. This is actually the correct optics for visual acuity. |
Digital Back Side
Progressive
Digital surfacing brings the progressive design to the back surface of the lens and no longer has a “varying” base curve “built in” since a single vision front base curve is used. This creates optical problems that must be corrected. |
Curve Correction Compensation
Optical designers must first correct the optical problems created by a Single Vision front curve. They are also unfortunately “using up” their design tools for “compensation correction” rather than incorporating the best enhancements for the patient. |