Patent ID: 6848788

Claim:
Spectacle lens comprising a distance portion designed for viewing at large distances, which include infinity; a near portion designed for viewing at short distances, including reading distances; and a progressive zone disposed between the distance portion and the near portion, in which the power of the spectacle lens increases from a value at a distance reference point located in the distance portion to a value at the near reference point located in the near portion along a curved principal line veering towards the nose, by an addition power; wherein the magnification varies monotonically from an extreme point in all radial direction; wherein the difference between the magnifications at the distance and near reference points is small, and wherein the absolute difference of the magnification between the near and the distance reference point is equal to or smaller than the values in the following table from which intermediate values can be obtained by linear interpolation: Add = 1.0 Add = 1.5 Add = 2.0 Add = 2.5 Add = 3.0 Do = −4.0 1.2 1.2 1.8 2.8 3.7 Do = −2.0 1.0 1.6 2.9 4.0 5.0 Do = 0 2.5 3.2 4.2 5.3 6.4 Do = 2.0 4.1 4.7 5.3 6.3 7.8 Do = 4.0 5.8 5.9 6.3 7.7 8.8 where the addition power Add is the difference of the mean powers when worn by a user in the near and distance reference points, and D 0 is the mean power when worn by a user at the distance reference point.