Optics: eye examining – vision testing and correcting – Spectacles and eyeglasses – Ophthalmic lenses or blanks
Reexamination Certificate
1998-09-28
2001-06-12
Sugarman, Scott J. (Department: 2873)
Optics: eye examining, vision testing and correcting
Spectacles and eyeglasses
Ophthalmic lenses or blanks
C351S177000
Reexamination Certificate
active
06244708
ABSTRACT:
BACKGROUND OF THE INVENTION
Contact lenses intended for correcting myopia (nearsightedness) or hypermetropia (farsightedness) have a central optical zone that imparts a negative or positive spherical correction (also referred to as power correction) to the lens. Zones peripheral to the optical zone are mainly provided for fitting. The term “spherical contact lens” is often used to denote a contact lens intended for correcting myopia or hypermetropia having spherical or near-spherical surfaces, as distinguished from lenses having a toroidal surface that imparts a cylindrical correction to compensate for an astigmatism. However, as known in the art, even though spherical posterior and anterior surfaces provide acceptable visual acuity, spherical aberration may be introduced into the lens due to the geometry of the lenses. One manner used to compensate for spherical aberration has involved providing a lens surface with asphericity in an attempt to eliminate the spherical aberration.
SUMMARY OF THE INVENTION
The present invention provides a method for obtaining contact lenses having improved visual acuity. The method comprising providing at least one of the anterior surface or the posterior surface of the contact lens with a conic section having a shape factor value within the range of about 0.3 to 2.0, the shape factor value being selected so as to adjust spherical aberration in the central optical zone to a value within the range of about −0.2 diopter to about −0.6 diopter and to a value that improves visual acuity.
According to various embodiments, the invention involves correlating conic section shape factors with aberration values within the range of about −0.2 to −0.6 diopter for a specific contact lens design, then determining the aberration value and associated shape factor that improves visual acuity.
Preferably, the shape factor value is selected so as to adjust spherical aberration in the central optical zone to a value within the range of about −0.2 diopter to about −0.6 diopter and to a value that optimizes visual acuity for a given lens design or power.
According to the other embodiments, the invention relates to providing contact lenses having optimized visual acuity over a series of contact lenses, each lens in the series having a different power correction. For each lens in the series conic shape factors are correlated with aberration values over the range of about −0.2 to −0.6 diopter, and the aberration value and associated shape factor that provides optimized visual acuity is determined for each contact lens in the series.
REFERENCES:
patent: 3482906 (1969-12-01), Volk
patent: 3933411 (1976-01-01), Winner
patent: 4195919 (1980-04-01), Shelton
patent: 4199231 (1980-04-01), Evans
patent: 5050981 (1991-09-01), Roffman
patent: 5220359 (1993-06-01), Roffman
patent: 5815239 (1998-09-01), Chapman et al.
patent: 2499256 (1982-08-01), None
patent: 94/23327 (1994-10-01), None
Biddle Graham W.
Chapman Judith E.
Comstock Timothy L.
Cox Ian G.
DeRyke Kevin J.
Bausch & Lomb Incorporated
Furr, Jr. Robert B.
Sugarman Scott J.
LandOfFree
Contact lenses providing improved visual acuity does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Contact lenses providing improved visual acuity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contact lenses providing improved visual acuity will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2447563