The term base curve is used to describe a curvature with the same radius of curvature of the front surface of lenses with different refractive powers.
In the traditional base curve system for progressive lenses one design is always optimized for a group of powers, with semi-finished lenses being prefabricated accordingly. Their number is limited, e.g. the same semi-finished lens is used for +3.00 D as for +4.00 cyl 1.00.
The  Gradal IndividualŪ and GradalŪ Short I individualized progressive lenses, however, are computed and produced separately for each individual prescription. The number of possible design variants is unlimited. Every wearer receives a design optimized for his or her own personal requirements.
Grundkurvenkonzept | |  Back |