Patent ID: 6579478
Filing Date: 2003-06-17
Classification: B29D,G02C,Y10S

Abstract:
A method of making a mold adapted to cast a progressive plastic eyeglass lens with a front face, a back face, a near vision correction zone, a far vision correction zone, and a vision transition zone between the near vision correction zone and the far vision correction zone, comprising the steps of:forming a progressive mold comprising (i) a back face with edges that is adapted to cast the front face of the lens, and wherein the back face of the mold comprises a near vision correction zone adapted to cast the near vision correction zone of the lens, a far vision correction zone adapted to cast the far vision correction zone of the lens, and a transition vision correction zone adapted to cast the transition vision correction zone of the lens, (ii) a front face, and (iii) side surfaces connecting the front face to the back face; and shaping the peripheral edges of the back face of the mold proximate to the near vision zone of the mold sufficiently to reduce vertical prism effects otherwise associated in a lens cast by the mold.