Abstract: A multifocal lens including annular zones wherein each annular zone is divided into at least two annular sub-zones. Preferably, no geometric or optical optical steps are present between annular zones or annular sub-zones. The refractive powers within the annular sub-zones are chosen such that the lens exhibits at least two diffractive powers and that at least one of those diffractive powers substantially coincides with the average refractive power of each annular zone.

Abstract: A multifocal diffractive lens includes at least two annular zone lenses. Provided between adjacent annular zone lenses is an optical step. Each annular zone lens exhibits a refractive power profile D.sub.g,i (r) wherein i is any i-th annular zone lens and r is the distance between an axis of the diffractive lens and a point on a back surface of the lens. The lens is further characterized in that an average power of zones i,j . . . are given by D.sub.av,i, D.sub.avj . . . respectively, and optical path lengths of light rays extending from an object point to a conjugated image point are different by the optical step for light rays transmitting through adjacent annular zone lenses. The annular zone lenses are shaped and positioned such that all of the average refractive powers D.sub.av,i, D.sub.avj . . . are substantially equal to a single value, D.sub.av.