Concentric ring, single vision lens designs are disclosed which improve the depth-of-focus of the lens relative to current spherical contact lenses or intraocular lenses by placing at least one additional peripheral optical radius on the front or back surface of the lens. A plurality of concentric annular rings are provided in the periphery of the optic zone of the lens. The arrangement of optic powers in the concentric annular rings includes a mixture of the basic spherical refractive power and other annular rings with less plus or greater minus spherical refractive power, arranged to mediate spherical aberrations and improve visual acuity. The concentric annular ring design corrects peripheral, aperture-dependent ocular aberrations in a discrete, zonal fashion.