An optical lens is disclosed. The optical lens has anterior and posterior surfaces and an optical center on its anterior surface. The anterior surface has an M-wave shape such that the surface curvature measured along a curve passing through the optical center varies substantially as a smoothed letter M in relationship to angular orientation about the optical center. 0 degrees angular orientation is substantially the point closest to the nose when the lens is worn and the central dip of the M occurs substantially at a point which is furthest from the nose when the lens is worn, corresponding to a 180 degree orientation, there being maxima of the M at substantially the uppermost and lowermost vertical extremes of the lens when it is worn, to 90 degree and 270 degree orientations, respectively. The surface curvature measured along a curve passing through the optical center is the surface curvature that is determined along a half meridian from a point on the perimeter of the cornea to a central point on the cornea.
