An improved ophthalmic lens is disclosed which has a plurality of
alternating power zones with a continuously varying power within each
zone, as well as in transition from one zone to another. In other words, a
plurality of concentric zones (at least two) are provided in which the
variation from far to near vision correction is continuous, i.e., from
near correction focal power to far correction focal power, then back to
near, and again back to far, or vice versa. This change is continuous
(progressive), without any abrupt correction changes, or "edges".
Two versions of the invention are disclosed. In the first version
continuous, alternating power variation is accomplished by a continuously
changing curvature of the lens posterior surface, thereby altering the
angle of impact of light rays on the eye.
In the second version continuous, alternating power variation is
accomplished by creating non-homogeneous surface characteristics having
refractive material indexes which continuously vary in the lens radial
direction (out from the optical axis).