Patent ID: 6669337
Filing Date: 2003-12-30
Classification: G02C

Abstract:
Spectacle lens comprisinga region (distance portion) designed for viewing at large distances and in particular â€œto infinityâ€ ; a region (near portion) designed for viewing at short distances and in particular â€œreading distancesâ€ ; and a progressive zone disposed between the distance portion and the near potion, in which a power of the spectacle lens increases from a value at a distance reference point located in the distance portion to a value at a near reference point located in the near portion along a curve (principal line) veering towards a nose; wherein an astigmatic deviation, i.e. a difference between a prescribed and an actual astigmatism along circles having a center lying 4 mm below a centration point and having a diameter of 10 to 40 mm satisfies the following conditions: two local minima occur which on a â€œright-hand side spectacle lensâ€  are located at 95Â°Â±10Â° (according to TABO) and at 280Â°Â±10Â°, and on a â€œleft-hand side spectacle lensâ€  at 85Â°Â±10Â° and 260Â°Â±10Â°; and two local maxima occur which on both a â€œright-hand side spectacle lensâ€  and also a â€œleft-hand-side spectacle lensâ€  are located at 215Â°Â±10Â° and 335Â°Â±10Â°.