The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 1992
Filed:
Dec. 19, 1989
Applicant:
Inventor:
Michael H Freeman, Clwyd, GB;
Assignee:
Pilkington Visioncare Holdings Inc., Menlo Park, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02C / ; G02B / ; A61F / ;
U.S. Cl.
CPC ...
3511 / ; 351161 ; 359565 ; 359569 ; 359570 ; 359571 ; 359575 ; 623-6 ;
Abstract
An artificial eye lens such as a contact lens or intra-ocular lens corrects astigmatism by two sets of substantially linear parallel zones arranged to diffract light predominantly into one order at one orientation, the spacing of the zones diminishing on either side of the linear axis. In addition circular diffraction zones may be provided to give both spherical and cylindrical power for astigmatism correction.