Laminar light-polarizing lens blank for producing prescription lens

A method of preparing a curved optical lens blank which comprises the steps of:

• providing a supply of a composite light-polarizing laminate, said laminate comprising, in order and in superposed relation, a first light-transmissive optically isotropic polymeric layer having a thickness in the range of 0.127 mm. to 1.91 mm., a light-polarizing layer, and a second light-transmissive polymeric layer, having a thickness from 3 to 100 times the thickness of said first light-transmissive polymeric layer sufficient to permit the grinding of material therefrom in the optical grinding of a concave surface of a lens to be formed from said laminar composite structure;
• cutting and removing from said supply of said light-polarizing laminate, a unitary portion of a size sufficient for the production therefrom of a curved lens;
• placing said unitary portion between opposed concave and convex platens, with the first light-transmissive layer of said portion positioned for shaping by said concave platen;
• heating and pressing said platens together, said pressing being sufficient to shape said unitary portion into a curved lens having a convex surface defined by the first light-transmissive layer thereof and a concave surface defined by the second light-transmissive layer thereof, each said surface having a radius of curvature corresponding substantially to the radius of curvature of the respective platen forming said surface;
• and
• removing said curved lens from between said platens.

A method of preparing a series of lens blanks for the production of prescription ophthalmic lenses therefrom which comprises the steps of:

• providing a supply of a composite light-polarizing laminate, said laminate comprising, in order and in superposed relation, a first light-transmissive optically isotropic polymeric layer having a thickness in the range of 0.127 mm. to 1.91 mm., a light-polarizing layer, and a second light-transmissive layer, said first light-transmissive layer being a thin layer relative to said second light-transmissive layer having a thickness from 3 to 100 times the thickness of said first light-transmissive polymeric layer sufficient to permit the grinding of material therefrom in the optical grinding of a concave surface of a lens to be formed from said laminar composite structure, said light-polarizing layer and at least the first of said first and second light-transmissive layers being aligned such that a principal index of refraction direction of said first light-transmissive layer is in substantial parallelism with the light-absorption axis of the light-polarizing layer;
• cutting and removing from said supply of said light-polarizing laminate, a unitary lens-blank of a size sufficient for the production therefrom of a curved lens;
• placing said unitary portion between opposed concave and convex platens, with the first light-transmissive layer of said portion positioned for shaping by said concave platen to a first convex lens surface having a refractive power in the range of from two to ten diopters;
• heating and pressing said platens together, said pressing being sufficient to shape said first unitary portion into a curved lens having said first convex lens surface and a concave surface defined by the second light-transmissive layer thereof, each said surface having a radius of curvature corresponding substantially to the radius of curvature of the respective platen forming said surface;
• removing the resulting curved lens blank from between said platens;
• and
• repeating each of said placing, heating-and-pressing and removing steps, using a series of concave platens for the shaping of unitary portions to each of a series of convex lens surfaces, each such surface having a different one of the remaining said refractive powers within said range of refractive powers;
• thereby to provide a series of lens blanks, each of which has a different convex lens surface within said range.