SPECTACLE LENS HAVING ASTIGMATIC POWER

摘要

The invention contemplates an astigmatic-power lens having at least one lens surface which differs from spherical or toric shape and which is characterized by the fact that, for each elemental region of said lens surface, the principal curvatures and the principal-curvature-direc-tions are so selected that the astigmatism of the spectacle lens and of the eye to be corrected are optimally adapted, as to direction and extent independant of the angular offset of the instantaneous line of sight from the central axis of the lens.