Abstract: Ophthalmic spectacle lenses with spherical powers between -0.25 and -12.00 diopters and cylindrical powers between -0.25 diopters and -4.00 diopters are disclosed. The lenses are provided with a convex spherical anterior surface and a concave aspherical posterior surface which also includes a correction for ocular astigmatism. The form of the posterior surface is determined by optimizing the aspheric curve along each principal meridian of the aspheric surface. The curve along each meridan of the posterior surface is described by the general equation:x=Ay.sup.2 +By.sup.4 +Cy.sup.6 +Dy.sup.8 +Ey.sup.10 . . .whereA determines the surface power of the curve at the vertex and is given by: ##EQU1## where F.sub.o is the required surface power of the curve at its vertex;n is the refractive index of lens material; andp is the eccentricity of the conic section at the vertex where p=1-e.sup.2, and e is the eccentricity of the aspheric surface.

Abstract: Ophthalmic spectacle lenses are provided with powers ranging from -20 to +7 diopters, for minus powered lenses, with a posterior surface of a hyperboloidal form and, for positive powered lenses with an anterior surface of a hyperboloidal form. Such hyperboloidal forms are computed by modifying the conventional formulae used for "Best Form" spherical lens surfaces from y.sup.2 =2000(n'-n).times./Fo-x.sup.2 to the formulae y.sup.2 =2000(n'-n).times./Fo-px.sup.2 ; where `p` has a value ranging from 0 to -4, Fo is the optical power of the lens at the intersection of the lens surface and the optic axis, Fo being given as follows: Fo=1000(n'-n)/ro where ro is the radius of the lens surface at the optic axis, and where (n'-n) is the difference between the refractive indices on opposite sides of the lens surface taken in the direction of light travel to the eye through the lens, all dimensions in the formulae being in millimeters and x and y being orthogonal co-ordinates.

Abstract: An intraocular lens for implantation in the anterior chamber of the human eye is provided. The lens is convexo-planar with the planar surface facing the cornea.