Specifically, the main benefit of allowing the designer to use both surfaces is the ability to simultaneously control focus and distortion. In single surface PALs, the designer must (and does) find a compromise between focus control and the reduction of distortion. When using a single surface progressive, the more distortion is controlled the less focus can be controlled (and vice versa). With two surfaces, it is possible to control both focus and distortion simultaneously.


Digital Surfacing DualOptix

• Two design surfaces
• Designs (D) on front and back, distance power (d) on back
• Increases flexibility and number of designs possible
• Greater accuracy, unlimited number of design elements
• Control of focus and distortion

Digital Surfacing Full Back

• Single surface format
• Design (D) and distance power (d) on back
• Greater accuracy, no inventory limitations
• More design elements possible
• Varilux DRx designs

Design Location Traditional surfacing

• Single surface pre-molded progressive
• Design (D) on front, distance power (d) on back
• Design limited by the number of standard base curves and adds
• Not capable of producing a back surface progressive