# US 2013/0155374 A1 · Method for designing and manufacturing a monofocal ophthalmic lens and corresponding lens

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- Number: US 2013/0155374 A1
- Document ID: US20130155374A1
- Status: Published application
- Kind: A1
- Application number: 13/720,419
- Filed: 2012-12-19
- Published: 2013-06-20
- Earliest claimed: 2011-12-19
- Assignees: Indo Internacional, S.A.
- Inventors: Juan Carlos Dürsteler López; Javier Vegas Caballero; Manuel Espinola Estepa; Sara Chamadoira Hermida; Glória Casanellas Peñalver
- Web page: https://patentgrep.com/patent/US20130155374A1

## CPC

- G02C 7/028: {Special mathematical design techniques}
- G02C 7/02: Lenses; Lens systems {; Methods of designing lenses}
- G02C 7/024: {Methods of designing ophthalmic lenses}
- G02C: SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES (trial frames for testing the eyes A61B3/04; goggles or eyeshields not having the same features as spectacles A61F9/00)

## Abstract

A method for designing and manufacturing a monofocal ophthalmic lens and corresponding lens. A surface of the monofocal ophthalmic lens is defined by: f(x,y)=a1+a2√{square root over (1−a3x2−a4y2)}+a5exp{a6x4+a7y4+a8x2y2} where a1-a8 are coefficients, a5 is other than 0 and at least one of a6, a7 and a8 is other than 0, including a hyperbolic component and an exponential component. The coefficients can be calculated by an iterative calculation and the merit function as follows: fm = [ ∑ i  α i  m i 2  ( β ) ] 1 / 2 where mi is a value of an optical property at a specific viewing angle β with respect to an optical axis of the lens, and αi is a weighting value.

## Claims

### Claim 1

A method for designing a surface of a monofocal ophthalmic lens, wherein said surface is defined by the formula (1):
f(x,y)=a1+a2√{square root over (1−a3x2−a4y2)}+a5exp{a6x4+a7y4+a8x2y2} (1)
wherein a1-a8 are coefficients and wherein a5 is other than 0 and at least one of a6, a7 and a8 is other than 0.

### Claim 2 (depends on 1)

The method according to claim 1, wherein said coefficients are calculated by an iterative calculation comprising the following steps:
[a] setting a value for a refractive index of the ophthalmic lens and for a base curve that will be used to manufacture the ophthalmic lens,
[b] setting sphere, cylinder and cylinder axis values for the ophthalmic lens,
[c] setting initial nominal values for a1-a8,
[d] calculating at least one optical property of a lens with said values,
[e] calculating a value of a merit function by the following formula (2):
fm
=
[
∑
i

α
i

m
i
2

(
β
)
]
1
/
2
(
2
)
where mi is a value of said optical property at a specific viewing angle β with respect to the optical axis of the lens, and αi is a weighting value,
[f] optimizing said merit function by new nominal values for said coefficients a1-a8, and
[g] repeating steps [c] to [f] until obtaining the desired optimization level.

### Claim 3 (depends on 2)

The method according to claim 2, wherein said merit function includes an oblique astigmatism value at 30°, and the αi value for the oblique astigmatism value is between 0.8 and 0.98.

### Claim 4 (depends on 2, 3)

The method according to claims 2 or 3, wherein said merit function includes a curvature of field value at 30°, and the αi value for the curvature of field value is between 0.02 and 0.2.

### Claim 5 (depends on 1, 2, 3)

The method according to claims 1 to 3, wherein said surface is a concave surface of said lens.

### Claim 6 (depends on 5)

The method according to claim 5, wherein a1 is equal to 0, a2 is equal to a radius of curvature in a center of said surface, with a negative sign, and a5 is equal to the radius of curvature in the center of said surface.

### Claim 7 (depends on 1, 6)

The method according to claims 1 and 6 wherein a6 is between −2×10−8 and 5×10−8 mm−4.

### Claim 8 (depends on 1)

The method according to claims 1, and 6, wherein a7 is between −2×10−8 and 1.2×10−7 mm−4.

### Claim 9 (depends on 1)

The method according to claims 1, and 6 wherein a8 is between −2×10−8 and 1.2×10−7 mm−4.

### Claim 10 (depends on 2, 3, 6)

The method according to claims 2, 3 and 6, wherein each of the coefficients of the formula (1) has a value between +/−30% of a corresponding nominal value obtained from said optimization.

### Claim 11

A method for manufacturing a monofocal ophthalmic lens, comprising:
machining a surface of said ophthalmic lens, where said surface is defined by the following formula:
f(x,y)=a1+a2√{square root over (1−a3x2−a4y2)}+a5exp{a6x4+a7y4+a8x2y2}
wherein a1-a8 are coefficients.

### Claim 12 (depends on 1, 2, 3, 6, 11)

The method according to claim 11, wherein said coefficients are obtained by the method of claims 1-3 and 6.

### Claim 13

A monofocal ophthalmic lens, comprising:
a surface defined by the following formula:
f(x,y)=a1+a2√{square root over (1−a3x2−a4y2)}+a5exp{a6x4+a7y4+a8x2y2}
wherein a1-a8 are coefficients.

### Claim 14 (depends on 1, 2, 3, 6, 13)

The lens according to claim 13, wherein said coefficients are obtained by the method of claims 1-3 and 6.