Simultaneous vision optical lens for correcting presbyopia

• US 4,976,534 A
• Filed: 01/22/1990
• Issued: 12/11/1990
• Est. Priority Date: 02/03/1989
• Status: Expired due to Fees

• Current Assignee: Essilor International SA
• Original Assignee: Essilor International SA
• Inventors: Miege, Christian, Obrecht, Gerard, Monteil, Pierre
• Primary Examiner(s): Sugarman, Scott J.
• Application Number:
  US07/468,282
• Time in Patent Office: 323 Days
• Field of Search: 351/160 R, 351/160 H, 351/161, 351/162, 623/5, 623/6
• US Class Current: 351/161
• CPC Class Codes: A61F 2/145 Corneal inlays, onlays, or lenses for refractive correction
• CPC Class Codes: A61F 2/16 Intraocular lenses
• CPC Class Codes: A61F 2/1618 Multifocal lenses
• CPC Class Codes: G02C 7/02 Lenses; Lens systems ; Methods of designing lenses
• CPC Class Codes: G02C 7/042 Simultaneous type
• CPC Class Codes: G02C 7/044 Annular configuration, e.g. pupil tuned
• CPC Class Codes: G02C 7/06 bifocal; multifocal ; progressive G02C7/041 takes precedence

Abstract

The proximity P of a simultaneous vision optical lens for correcting presbyopia is defined as the reciprocal of the distance D at which a light ray parallel to and at a distance h from its axis crosses the axis after passing through the lens. The curve representing the proximity P of the lens lies between a lower envelope curve P_inf and an upper envelope curve P_sup satisfying the following equations:

P.sub.inf =f(h)=(ΣA'"'"'.sub.i h.sup.i)+P.sub.VL

P.sub.sup =f(h)=(ΣA".sub.i h.sup.i)+P.sub.VL

in which P_VL is the proximity for distant vision and A'"'"'_i, A"_i are numeric coefficients depending on the proximity addition added for near vision to the proximity for far vision. The lens may be implemented as a contact lens, an intra-ocular implant or an intra-corneal lens.

Claims

1. Progressive simultaneous vision optical lens for correcting presbyopia in which the curve representing its proximity P defined as the reciprocal in diopters of the distance D at which a light ray parallel to and at a distance h from its axis crosses the axis after passing through the lens lies within an area between a lower envelope curve P_inf and an upper envelope curve P_sup defined by nth and hth degree polynomials and satisfying the following equations:

space="preserve" listing-type="equation">P.sub.inf =f(h) =(Σ

A'"'"'.sub.i h.sup.i)+P.sub.VL

space="preserve" listing-type="equation">P.sub.sup =f(h)=(Σ

A".sub.i h.sup.i)+P.sub.VL (I)

in which P_VL is the proximity needed for far vision and A'"'"'_i, A"_i are the coefficients of the various polynomials depending on the value of the proximity addition δ

₁ =A_DD corresponding to the degree of presbyopia of the wearer, the values of these coefficients being substantially as follows;

space="preserve" listing-type="tabular">______________________________________ for A.sub.DD = 1.5 D;

A'"'"'0 = 12.532267 A"0 = 16.9452 A'"'"'1 = -92.695892 A"1 = -106.8394 A'"'"'2 = 305.16919 A"2 = 302.62347 A'"'"'3 = -513.44922 A"3 = -443.97601 A'"'"'4 = 476.63852 A"4 = 362.53815 A'"'"'5 = -247.99097 A"5 = -166.29979 A'"'"'6 = 67.868942 A"6 = 40.015385 A'"'"'7 = -7.6131396 A"7 = -3.9203446 for A.sub.DD = 2 D;

A'"'"'0 = 23.56555 A"0 = 14.368889 A'"'"'1 = -182.77804 A"1 = -87.219223 A'"'"'2 = 605.05684 A"2 = 244.35987 A'"'"'3 = -1 024.1053 A"3 = -337.92626 A'"'"'4 = 962.99613 A"4 = 241.37509 A'"'"'5 = -511.24120 A"5 = -85.757212 A'"'"'6 = 143.7355 A"6 = 12.008102 A'"'"'7 = -16.663562 for A.sub.DD = 2.5 D;

A'"'"'0 = -28.307575 A"0 = 2.874459 A'"'"'1 = 190.37743 A"1 = 11.541159 A'"'"'2 = -445.545294 A"2 = -35.715782 A'"'"'3 = 512.44763 A"3 = 37.849808 A'"'"'4 = -315.3125 A"4 = -19.0199096 A'"'"'5 = 99.678413 A"5 = 4.2867818 A'"'"'6 = -12.731333 A"6 = -0.28934118 for A.sub.DD = 3 D;

A'"'"'0 = 22.19555 A"0 = 57.071102 A'"'"'1 = -157.74065 A"1 = -357.09277 A'"'"'2 = 529.74104 A"2 = 1 000.8899 A'"'"'3 = -918.56382 A"3 = -1 509.5112 A'"'"'4 = 881.73279 A"4 = 1 311.576 A'"'"'5 = -475.73774 A"5 = -657.94254 A'"'"'6 = 135.48897 A"6 = 177.01095 A'"'"'7 = -15.888513 A"7 = -19.763759 ______________________________________

and, for possible intermediate additions whose value δ

is between two above-mentioned addition values δ

₁ and δ

₁ +0.5, the envelope curves of these intermediate additions are deduced from the envelope curves corresponding to δ

₁ and δ

₁ +0.5 by the equations;

##EQU3##

2. Optical lens according to claim 1 wherein the curve representative of its proximity satisfies the following equation:

space="preserve" listing-type="equation">P.sub.nom =f(h)=(Σ

A.sub.i h.sup.i)+P.sub.VL

with, subject to the same conditions as previously;

space="preserve" listing-type="tabular">______________________________________ for A.sub.DD = 1.5 D;

A0 = 1.8983333 A1 = -3.8368794 A2 = 17.797017 A3 = -34.095052 A4 = 28.027344 A5 = -10.464243 A6 = 1.464837 A7 = 0 for A.sub.DD = 2 D A0 = 12.637321 A1 = -85.632629 A2 = 269.61975 A3 = -425.09732 A4 = 361.26779 A5 = -168.43481 A6 = 40.408779 A7 = -3.8719125 for A.sub.DD = 2.5 D A0 = -12.716558 A1 = 100.95929 A2 = -240.63054 A3 = 275.14871 A4 = -167.1658 A5 = 51.982597 A6 = -6.5103369 for A.sub.DD = 3 D A0 = 39.633326 A1 = -257.41671 A2 = 765.31546 A3 = -1 214.0375 A4 = 1 096.6544 A5 = -566.84014 A6 = 156.24996 A7 = -17.826136 ______________________________________

3. Optical lens according to claim 1 wherein the local value of the proximity gradient dP/dh does not exceed 5 diopters per millimeter continuously over a proximity range greater than 0.25 diopters.

4. Optical lens according to claim 1 wherein the mean proximity gradient G_VP for near vision and the mean proximity gradient G_VL for distant vision are related as follows:

space="preserve" listing-type="equation">G.sub.VP /G.sub.VL >

2.

5. Ophthalmic lens according to claim 1 wherein the surface S_VP of the transition area contributing usefully to near vision and the surface S_VL of the transition area contributing usefully to far vision are related as follows:

space="preserve" listing-type="equation">S.sub.VL /S.sub.VP ≧

3.