Patent · US Expired

Soft contact lens having toric rear face and rotationally symmetrical front face

US5455641A · kind A · utility

20Cited by

7References

9Claims

0Family size

Assignee

Ciba-Geigy · US

Inventors

Christoph Hahne · Essen, DE
Peter Hofer · Liestal, CH
Willi Horner · Pocking, DE
Martin Reichner · Aschaffenburg, DE

Key dates

Filing date	Dec 22, 1994
Grant date	Oct 3, 1995
Priority date	—
Expiry date	Dec 22, 2014

Classification

Technology area (CPC G)Physics
CPC primaryG02C2202/08
WIPO fieldOptics
WIPO sectorInstruments

Abstract

The soft toric contact lens has a substantially rotationally symmetrical front face optionally having a rotationally symmetrical lenticular construction, and a substantially aspherical, especially ellipsoidal, rear face. The optically active central region of the rear face is toric. Shifting the torus to the central region of the lens rear face results in lenses that are economic to produce, are of wearable thickness and are straightforward to fit.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.