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:
Jan. 27, 2004
Filed:
Jan. 31, 2002
Francoise Ahsbahs, Saint Maur des Fosses, FR;
Pierre Devie, Chevily Larue, FR;
Essilor International, Charenton Cedex, FR;
Abstract
A progressive multifocal ophthalmic lens having a far vision region, an intermediate vision region and a near vision region, a main meridian of progression passing through said three regions, and a power addition equal to a difference in mean sphere between a near vision region control point and a far vision region control point is provided. The lens has a progression length less than 12 mm, defined as the vertical distance between a mounting center and a point on the meridian where mean sphere is greater than mean sphere at the far vision control point by 85% of the power addition value. To ensure good visual characteristics not only around the meridian, but also in regions of extra-foveal vision, the ratio between the integral of the product of cylinder times the norm of sphere gradient, on a 40 mm diameter circle centered on the center of the lens, and the product of the area of this circle, power addition and a maximum value of the norm of sphere gradient over that part of the meridian comprised within this circle is less than 0.14.