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Progressive addition power lens

  • US 7,033,023 B2
  • Filed: 08/17/2004
  • Issued: 04/25/2006
  • Est. Priority Date: 05/31/2002
  • Status: Expired due to Term
First Claim
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1. A progressive lens comprising a surface having a variable height and including a distance area and a reading area, wherein a contour defining an area of constant mean power in the distance area is an ellipse with a ratio of major axis to minor axis in the range of about 1.1 to 3.0, and mean power M over the lens surface varies according to a set of curves forming iso-mean power contours on the lens surface wherein mean power M varies along a connecting path extending from a first point in the distance area to a second point in the reading area according to a function of the form:

  • M

    (y)
    =MD+[MR-MDD]

    [1-cos

    (π





    yD-yyD-yR
    )
    ]
    where MD is mean power specified at a first point (0, YD) in the distance area and MR is mean power specified at the second point (0, YR) in the reading area.

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