Accommodating intraocular lens and lens series and method of lens selection

An intraocular lens for the correction of the axial refractive error and the accommodative insufficiency of the post-surgical aphakic eye, made of homogeneous transparent optical material, for placement in the posterior chamber of the human aphakic eye, of continuously and regularly increasing refractive power peripheralward, of a diameter between 4.5 mm and 7 mm and of thickness between 0.65 mm and 1 mm, with at least one surface of said intraocular lens a positive aspheric surface of revolution having an apical umbilical point at which the derivative of curvature vanishes, said surface increasing continuously and regularly in curvature and refractive power from said apical umbilical point to its periphery and where the magnitude and shape of said surface is defined mathematically by means of the following expression:

• y=(Ax+Bx.sup.2).sup.1/2 +Cx.sup.(p) +Dx.sup.(q) +Ex.sup.(z),
• where A=2r.sub.apex, B=(e.sup.2 -1), e being the eccentricity at the apex of said surface, where C, D, and E are integral or non-integral coefficients of x.sup.(p), x.sup.(q), and x.sup.(z) respectively, and where p, q, and z can be integral or non-integral exponents of x, and where r ranges from 5 mm to 150 mm, where e ranges from 0.0 to 4.0, where at least one of the values of C, D, and E is other than zero, values of C, D, and E ranging from 0.0 to .+-.9, the values of p, q, and z range from a value of 0.5 to 6.0.