Method for providing an ophthalmic lens to a wearer

Abstract

A method for providing an ophthalmic lens to a wearer including: providing the wearer's astigmatism features measured at a first proximity; providing the wearer's astigmatism features measured at a second proximity, wherein the second proximity is greater than the first proximity; determining customized wearer's astigmatism features based on the combination resulting of linear combinations of the wearer's astigmatism features measured at the first proximity and of the wearer's astigmatism features measured at the second proximity; and applying the customized astigmatism features to the ophthalmic lens.

Claims

1. A method for providing an ophthalmic lens to a wearer comprising: providing wearer's astigmatism features measured at a first proximity, the wearer's astigmatism features comprising a modulus of astigmatism AST_MOD1 and an axis of astigmatism AST_AX1; providing wearer's astigmatism features measured at a second proximity, the wearer's astigmatism features comprising a modulus of astigmatism AST_MOD2 and an axis of astigmatism AST_AX2, wherein the second proximity is greater than the first proximity; determining customized astigmatism features (AST_MOD_C, AST_AX_C) based on a combination of the wearer's astigmatism features measured at the first proximity (AST_MOD1, AST_AX1) and of the wearer's astigmatism features measured at the second proximity (AST_MOD2, AST_AX2); applying the customized astigmatism features (AST_MOD_C, AST_AX_C) to the ophthalmic lens to provide a wearer astigmatism correction (AST_MOD_C, AST_AX_C) for both the first proximity and second proximity; wherein the combination of the wearer's astigmatism features measured at the first proximity and of the wearer's astigmatism features measured at the second proximity results of linear combinations wherein: AST_MOD_C=a.Math.AST_MOD1+b.Math.AST_MOD2; AST_AX_C=c.Math.AST_AX1+d.Math.AST_AX2; parameters a, b, c and d are positive or nil values, each being equal or less to 1; parameter a value is different from 1 and/or parameter c value is different from 1; a+b=1 and c+d=1.

2. A method for providing an ophthalmic lens as claimed in claim 1, further comprising providing the wearer's prescribed mean refractive power for the first proximity.

3. A method for providing an ophthalmic lens as claimed in claim 1, wherein the lens is an ophthalmic single vision lens, and the customized astigmatism features (AST_MOD_C, AST_AX_C) are applied to the whole surface of the lens.

4. A method for providing an ophthalmic lens as claimed in claim 1, wherein the lens is an ophthalmic progressive addition lens, and the customized astigmatism features (AST_MOD_C, AST_AX_C) are applied to the meridian line of a target lens used to calculate by computer the ophthalmic lens for the wearer the by performing an optimization with the target lens.

5. A method for providing an ophthalmic lens as claimed in claim 1, wherein the first proximity Prox1 and the second proximity Prox2 are chosen within the list of (Prox1=Far vision proximity, Prox2=Near vision proximity); (Prox1=Far vision proximity, Prox2=Intermediate vision proximity); (Prox1=Intermediate vision proximity, Prox2=Near vision proximity).

6. A method for providing an ophthalmic lens as claimed in claim 5, wherein the first proximity is the far vision proximity.

7. A method for providing an ophthalmic lens as claimed in claim 6, wherein values of parameters a, b, c and d are chosen according to a set of rules as a function of needs of the wearers.

8. A method for providing an ophthalmic lens as claimed in claim 7, wherein the wearer's needs refer to far vision and to near and/or intermediate vision(s) visual tasks, and wherein values of parameters a, b, c and d are chosen according to following rules: a=c=0 and b=d=1, when abs(AST_MOD2AST_MOD1)<0.5 Diopter and when abs(AST_AX2AST_AX1)<5; a=d=0 and c=b=1, when abs(AST_MOD2AST_MOD1)<0.5 Diopter and when abs(AST_AX2AST_AX1)5; b=c=0 and a=d=1, when abs(AST_MOD2AST_MOD1)0.5 Diopter and when abs(AST_AX2AST_AX1)<5; a, b, c and d values are each a value equal or less to and are each a value equal or greater to , for example are each a value equal to 0.5, when abs(AST_MOD2AST_MOD1)0.5 Diopter and when abs(AST_AX2AST_AX1)5.

9. A method for providing an ophthalmic lens as claimed in claim 7, further comprising wherein questions are asked to the wearer to determine a main visual task and preferred viewing distance, PREFDIST, corresponding to the visual task, and wherein values of parameters a, b, c and d are chosen according to the preferred viewing distance, PREFDIST.

10. A method for providing an ophthalmic lens as claimed in claim 7, further comprising wherein visual acuity of the wearer is measured using trial glasses, and wherein values of parameters a, b, c and d are chosen according to the wearer's visual acuity.

11. A method for providing an ophthalmic lens as claimed in claim 1, implemented by a computer.

12. A method of manufacturing an ophthalmic lens comprising: surfacing at least a face of a lens blank so as the astigmatism features (AST_MOD, AST_AX) of the manufactured ophthalmic lens fulfil the astigmatism features calculated according to claim 1.

13. A method of manufacturing an ophthalmic lens as claimed in claim 2, wherein the lens blank is a semi-finished lens blank comprising a finished front face and an unfinished back face and wherein only the unfinished back face is surfaced.

14. A pair of spectacle lenses for a given wearer comprising two ophthalmic lenses where the astigmatism features (AST_MOD, AST_AX) of each ophthalmic lens of the pair are determined according to the method of claim 1.

15. A method for providing an ophthalmic lens as claimed in claim 8, wherein the wearer's needs refer to far vision and to near and/or intermediate vision(s) visual tasks and where values of parameters a, b, c and d are chosen according to following rules: a=c=0 and b=d=1, when abs(AST_MOD2AST_MOD1)<0.5 Diopter and when abs(AST_AX2AST_AX1)<5; a=d=0 and c=b=1, when abs(AST_MOD2AST_MOD1)<0.5 Diopter and when abs(AST_AX2AST_AX1)5; b=c=0 and a=d=1, when abs(AST_MOD2AST_MOD1)0.5 Diopter and when abs(AST_AX2AST_AX1)<5; a, b, c and d values are each a value equal to 0.5, when abs(AST_MOD2AST_MOD1)0.5 Diopter and when abs(AST_AX2AST_AX1)5.

Description

EXAMPLES

(1) In the following examples, the first proximity Prox1 is the far vision proximity and the wearer's prescribed mean refractive power for the first proximity Prox1 is the prescribed sphere SPH.sub.p, the wearer's astigmatism features measured at a first proximity Prox1 (AST_MOD1, AST_AX1) are respectively the prescribed astigmatism value CYL.sub.p and the prescribed axis AXIS.sub.p, where said prescribed data are measured when the wearer is looking in a far vision gaze direction at a far distance. In said examples, the wearer's astigmatism features measured at the second proximity Prox2 (AST_MOD2, AST_AX2) are respectively the measured near vision astigmatism value CYL.sub.NV and the measured near vision axis AXIS.sub.NV, where said data are measured when the wearer is looking in a near vision gaze direction at a near distance.

(2) First set of examples (following examples 1 to 6) where the combination of the wearer's astigmatism features measured at the first proximity Prox1 and of the wearer's astigmatism features measured at the second proximity Prox2 results of following linear combinations: AST_MOD_C=a.Math.AST_MOD1+b.Math.AST_MOD2; AST_AX_C=c.Math.AST_AX1+d.Math.AST_AX2; Parameters a, b, c and d are positive or nil values, each being equal or less to 1; Parameter a value is different from 1 and/or parameter c value is different from 1; a+b=1 and c+d=1.

(3) According to a first embodiment (following examples 1 to 3) of these first set of examples:

(4) a=c=0 and b=d=1, and: AST_MOD_C=AST_MOD2; AST_AX_C=AST_AX2;

Example 1

(5) The ophthalmic lens is an ophthalmic single vision lens, and measurements made give following results: SPH.sub.p=5D, CYL.sub.p=1D and AXIS.sub.p=10, CYL.sub.NV=1.25D, AXIS.sub.NV=13;

(6) Here above and in the following, D refers to Diopter unit.

(7) The customized wearer's astigmatism features are following:

(8) SPH=5D, AST_MOD_C=1.25D and AST_AX_C=13.

Example 2

(9) The ophthalmic lens is a plano ophthalmic single vision lens, and measurements made give following results: SPH.sub.p=0D, CYL.sub.p=0D and AXIS.sub.p=0, CYL.sub.IV=0.25D, AXIS.sub.IV=3;

(10) The customized wearer's astigmatism features are following:

(11) SPH=0D, AST_MOD_C=0.25D and AST_AX_C=3.

Example 3

(12) The ophthalmic lens is an ophthalmic progressive addition lens, and measurements made give following results: SPH.sub.p=5D, CYL.sub.p=1D and AXIS.sub.p=10, ADD.sub.p=2D, CYL.sub.NV=1.37D, AXIS.sub.NV=7;

(13) The customized wearer's astigmatism features are following:

(14) In far vision: SPH.sub.FV=5D, AST_MOD_C.sub.FV=1.37D and AST_AX_C.sub.FV=7.

(15) In near vision: SPH.sub.NV=3D, AST_MOD_C.sub.NV=1.37 and AST_AX_C.sub.NV=7.

(16) According to a second embodiment (following example 4) of these first set of examples:

(17) a=d=0 and b=c=1, and: AST_MOD_C=AST_MOD2; AST_AX_C=AST_AX1;

Example 4

(18) The ophthalmic lens is an ophthalmic single vision lens, and measurements made give following results: SPH.sub.p=5D, CYL.sub.p=1D and AXIS.sub.p=10, CYL.sub.NV=1.25D, AXIS.sub.NV=18;

(19) The customized wearer's astigmatism features are following:

(20) SPH=5D, AST_MOD_C=1.25D and AST_AX_C=10.

(21) According to a third embodiment (following example 5) of these first set of examples:

(22) b=c=0 and a=d=1, and: AST_MOD_C=AST_MOD1; AST_AX_C=AST_AX2;

Example 5

(23) The ophthalmic lens is an ophthalmic single vision lens, and measurements made give following results: SPH.sub.p=5D, CYL.sub.p=1D and AXIS.sub.p=10, CYL.sub.NV=0.25, AXIS.sub.NV=13;

(24) The customized wearer's astigmatism features are following:

(25) SPH=5D, AST_MOD_C=1D and AST_AX_C=13.

(26) According to a fourth embodiment (following example 6) of these first set of examples:

(27) a=b=c=d=0.5, and: AST_MOD_C=(AST_MOD1+AST_MOD2)/2; AST_AX_C=(AST_AX1+AST_AX2)/2;

Example 6

(28) The ophthalmic lens is an ophthalmic single vision lens, and measurements made give following results: SPH.sub.p=5D, CYL.sub.p=1D and AXIS.sub.p=10, CYL.sub.NV=2D, AXIS.sub.NV=20;

(29) The customized wearer's astigmatism features are following:

(30) SPH=5D, AST_MOD_C=1.5D and AST_AX_C=15.

(31) Second set of examples where the combination of the wearer's astigmatism features measured at the first proximity Prox1 and of the wearer's astigmatism features measured at the second proximity Prox2 results of following linear combinations: AST_MOD_C=a.Math.AST_MOD1+b.Math.AST_MOD2; AST_AX_C=c.Math.AST_AX1+d.Math.AST_AX2; One chooses the values of parameters a, b, c and d according to one of following CASE 1, CASE 2, CASE 3, CASE 4: CASE 1: a=c=0 and b=d=1; CASE 2: a=d=0 and b=c=1; CASE 3: b=c=0 and a=d=1; CASE 4: a=b=c=d=0.5; The choice of CASE 1, CASE 2, CASE 3 and CASE 4 is made according to a set of rules as a function of the wearer's needs.

(32) According to a first embodiment of these second set of examples, the wearer's needs refer to far vision and to near and/or intermediate vision(s) visual tasks and the set of rules corresponding to the wearer's needs is following: CASE 1, when abs(AST_MOD2AST_MOD1)<0.5 Diopter and when abs(AST_AX2AST_AX1)<5; CASE 2, when abs(AST_MOD2AST_MOD1)<0.5 Diopter and when abs(AST_AX2AST_AX1)5; CASE 3, when abs(AST_MOD2AST_MOD1)0.5 Diopter and when abs(AST_AX2AST_AX1)<5; CASE 4, when abs(AST_MOD2AST_MOD1)0.5 Diopter and when abs(AST_AX2AST_AX1)5.

(33) According to a second embodiment of these second set of examples, set of rules as a function of the wearer's needs is following: the method further comprises a step where questions are asked to the wearer to determine his main visual task and the preferred viewing distance, PREFDIST, corresponding to said visual task, and the choice of parameter a,b,c and d is made according to the preferred viewing distance, PREFDIST.

(34) According to an example related to said embodiment: the wearer explains that he spends long time periods when looking at far distances and PREFDIST is defined as corresponding to a far vision visual task; choice of a>b and/or c>d recommended; the wearer explains that he spends long time periods when looking at near distances and PREFDIST is defined as corresponding to a near vision visual task; one can choose b>a and/or d>c; the wearer explains that he spends long time periods when looking at intermediate distances and PREFDIST is defined as corresponding to an intermediate vision visual task; one can choose a=b=0.5 and/or c=d=0.5.

(35) According to a third embodiment of these second set of examples, set of rules as a function of the wearer's needs is following: the method further comprises a step where visual acuity of the wearer is measured thanks to trial glasses, and wherein values of parameters a, b, c and d are chosen according to the wearer's visual acuity. According to an example, visual acuity is measured in both far vision and near vision; According to another example, visual acuity is measured in both far vision and intermediate vision. This embodiment may be combined with previous one where questions are asked to the wearer to determine his main visual task and a preferred viewing distance, PREFDIST, corresponding to said visual task is determined. Parameters a, b, c, d are then determined so that global acuity, being the average acuity between far vision and near vision or far vision and intermediate vision, is maximized.

(36) According to an embodiment, the method for providing an ophthalmic lens to a wearer according to the present invention comprises a sub-method for determining the wearer's astigmatism features, the sub-method comprising:

(37) using a vision-compensating device allowing observation along an optical axis (X) of observation with an optical correction of variable power comprises a lens having, along the optical axis, a spherical power that is variable as a function of a first control, and an optical assembly generating, along the optical axis, a cylindrical correction that is variable as a function of at least one second control applied to said optical assembly; said vision-compensating device also comprises a module for receiving at least one setpoint for said optical correction and a module for determining the first control and the second control depending on said setpoint by means of a mode taking into account the distance (2) separating said lens and said optical assembly.

(38) The vision-compensating device, usually referred as a phoropter, used in said sub-method is disclosed in more details in PCT Application number WO2016FR51827, published as WO2017013343 (A1) (VISION-COMPENSATING DEVICE, METHOD FOR CONTROLLING A VISION-COMPENSATING DEVICE AND BINOCULAR OPTOMETRY DEVICE), which is hereby incorporated by reference.

(39) Thanks to this sub-method, quick and accurate wearer's astigmatism features can be obtained.

(40) According to an embodiment, the method for providing an ophthalmic lens to a wearer according to the present invention comprises a sub-method for determining a dioptric parameter corresponding to the wearer's astigmatism features, the sub-method comprising: a set-up step, during which a test optical element having a dioptric function having a specific value of the dioptric parameter to be determined is provided to the person and the person is required to look at a visual target using the test optical element, a data collecting step, during which evaluation data and certitude data are collected, the evaluation data being indicative of the visual assessment expressed by the person looking at the visual target using the test optical element and certitude data being indicative of the degree of certainty of the person upon expressing the visual assessment,

(41) wherein the set-up and data collecting steps are repeated by varying the value of the dioptric parameter of the test optical element, and

(42) the method further comprises: a global analyzing step, during which for each value of the dioptric parameter tested during the set-up and data collecting step a value a degree of certainty of the person is determined and the value of the dioptric parameter of the person is determined based on the values of degree of certainty of the person.

(43) Said sub-method is disclosed in more details in EP application number 16305945.4, filed on 22 Jul. 2016, which is hereby incorporated by reference.

(44) The present method can be implemented for providing numerous ophthalmic lenses types to a wearer, such as ophthalmic single vision lenses, multifocal lenses, such bifocal or trifocal ophthalmic lenses, ophthalmic progressive addition lenses, occupational lenses (intended to provide correct vision for both near and intermediate vision) or antifatigue lenses intended to provide correction vision for far vision and to provide small addition power for near or intermediate vision). Among ophthalmic progressive addition lenses, ophthalmic lenses may be suitable for far vision and intermediate vision and near vision (also called standard ophthalmic progressive addition lenses), or for far vision and intermediate vision or for intermediate vision and near vision.