Patent ID: 11953759
Assignee: RODENSTOCK GMBH
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 12:
13. A lens having a first reference point and a near reference point, wherein:
an astigmatism at the near reference point deviates by at least 0.5 dpt from a value predetermined by a prescription for the astigmatism at the near reference point, or deviates by at least 0.5 dpt from the astigmatism at the first reference point; and
a difference of a vertical prismatic effect at the first reference point and a vertical prismatic effect at the near reference point deviates by at least 0.5 cm/m from a value ΔPr90; or
a difference of a horizontal prismatic effect at the first reference point and a horizontal prismatic effect at the near reference point deviates by at least 0.5 cm/m from a value ΔPr90, wherein

ΔPr90=−0.1(−2.5+0.05SN902+(SF90+0.8Add90)(yBN−yBF)+0.025Add90(yBN2−yNF2));

and

ΔPr0=0.05(SF0+SN0)(xBN+xBF),

and wherein:
xBF refers to the horizontal coordinates of the first reference point;
xBN refers to the horizontal coordinates of the near reference point;
yBF refers to the vertical coordinates of the first reference point;
yBN refers to the vertical coordinates of the near reference point;
SF90 refers to the refractive power in the vertical direction at the first reference point;
SN90 refers to the refractive power in the vertical direction at the near reference point;
Add90=SN90−SF90 refers to the vertical addition;
SF0 refers to the refractive power in the horizontal direction at the first reference point;
SN0 refers to the refractive power in the horizontal direction at the near reference point; and
Add0=SN0−SF0 refers to the horizontal addition.