MXPA96001668A

MXPA96001668A - Designs of ring lens concentrated annular parapresbiopes astigmati

Info

Publication number: MXPA96001668A
Application number: MXPA/A/1996/001668A
Authority: MX
Inventors: H Roffman Jeffrey; V Menezes Edgar
Original assignee: Johnson & Johnson Vision Products Inc
Priority date: 1995-05-04
Filing date: 1996-05-03
Publication date: 1997-12-01

Abstract

The present invention relates to a ring lens, concentric, multiple focus for astigmatic presbiops, characterized in that it comprises: a. the lens having a frontaly surface an opposite posterior surface, in which one of the fontal and posterior surfaces defines a central area, comprising a circular disk having a surface corresponding to a remote optical power, of basic prescription, and b. a plurality of annular rings surrounding the central area and comprising at least one annular ring of near optical power and at least one annular ring of optical power which corresponds to the cylindrical optical power of the patient's prescription, to provide visual acuity for astigmatic presbiopes

Description

DESIGN OF CONCENTRIC ANULAR RING LENS FOR ASTIGMATIC PRESBIOPS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to annular ring lens designs, concentric for astigmatic presbyopia. More particularly, the subject invention pertains to such concentric annular ring lens designs, wherein at least one surface of the lens has a circular central portion and a plurality of annular rings with at least three separate spherical optical powers, which correspond to a prescription for the astigmatic presbyopic patient. The three separated spherical optical powers correspond to 1) a spherical Rx prescription, of basic distance, 2) a spherical prescription Rx aggregate, close and 3) a spherical prescription that corresponds to all or preferably a fraction of the prescription Rx cylindrical. 2. Discussion of the Previous Technique The present invention pertains to ophthalmic lenses and in particular to contact lenses, such as soft hydrogel contact lenses and intraocular lenses, designed particularly for astigmatic presbyopia. It is well known that as an individual ages, the eye is less able to accommodate, ie, flex the natural lens in the eye to focus on objects that are relatively close to the observer. This condition is referred to as presbyopia and presbyopia have been based on lenses for glasses or other lenses that have many different regions with different optical powers, for which the user can shift his vision to find the appropriate optical power for the object or objects on which the observer wishes to focus on. Similarly, for a person who has had the natural eye lens removed due to a cataract condition and an intraocular lens inserted as a replacement, the ability to adjust the lens (accommodate) to the distance of the object being observed is completely absent. In this case, the provided lens is usually adjusted to a single focal power of infinite distance, and the glasses are used to provide the additional positive optical power, necessary for the closest approach to vision. For such a patient, a multifocal, functional lens would be particularly useful. It is known that for astigmatic individuals, the astigmatic eye forms an image, which contains three main regions. 1. The spherical power is focused as a line; 2. The cylindrical power is also focused as a line, perpendicular to the line of the spherical image; 3. Between the two, a circular image is formed, known as the "circle of least confusion". It is also known in the art that under certain circumstances the brain can effectively discriminate between images competing separately, accepting an image in focus and rejecting an out of focus image. Toric contact lenses are usually prescribed for astigmatic patients with either corneal or lenticular astigmatism and have an optical, cylindrical surface / power, which is used to correct astigmatism in a user. Statistically, astigmatism usually occurs in people, mainly around either the horizontal axis or the vertical axis, but also in variable axial locations with respect to them. In the prior art a separate type of toric contact lens was required for each different toric optical power and also for each different orientation of the toric cylindrical axis of the contact lens, which were required to accommodate different patients with different amounts of astigmatism along the different axes. Accordingly, an inventory of toric contact lenses, or plastic molded parts for molding toric contact lenses, include many different combinations of toric location and toric optical power. A significant advantage of the present invention is a substantial reduction resulting in the number of units kept in stock inventory (different possible prescriptions held in inventory).

BRIEF DESCRIPTION OF THE INVENTION Accordingly, it is a principal object of the present invention to provide concentric lens designs for astigmatic presbiops. Another object of the present invention is the provision of annular ring lens designs, concentric for astigmatic presbiops, which results in a substantial reduction in the number of units kept in storage, kept in inventory.

Another object of the subject invention is the provision of concentric lens designs for astigmatic prespipes, which comprises at least one surface, which has a circular central portion and a plurality of concentric annular rings, with at least three optical powers separate, corresponding to a prescription for a patient and corresponding to 1) a spherical prescription Rx basic distance, 2) Rx spherical prescription added, close and 3) a spherical prescription that corresponds to the total or preferably a fraction of the Cylindrical Rx prescription. A presbiope requires a lens with a spherical prescription of basic distance, to focus on distant objects and a close spherical prescription (added) to focus on nearby objects. In addition to this, an astigmatic presbiope requires an astigmatic correction, usually in the nature of a cylindrical prescription, which specifies both the cylindrical optical power and the cylindrical axis orientation. The present invention takes into account the cylindrical prescription in the design of the lens, but does not use a cylindrical optical surface. In contrast, the present invention recognizes that the brain can effectively discriminate between competing images separately by accepting an image in focus and rejecting an out-of-focus image. Accordingly, the present invention provides a portion of the lens with a spherical force corresponding to the cylindrical prescription, or preferably a fraction of the full cylindrical prescription and relies on the brain to discriminate and accept an image in focus to compensate for astigmatism. of the patient. The spherical surface corresponding to the cylindrical prescription provides a lens with an improved depth of field for cylindrical astigmatics. The present invention is directed to designs of a concentric lens for astigmatic presbiopes, which provide: (i) the ability to address the visual prescription requirements of approximately 25% of the vision correction market; (ii) the ability to provide high volume / low cost contact lenses with a minimum number of units held in stock in the inventory, comparable to current spherical contact lenses; (iii) the ability to eliminate the requirement for the stabilization characteristics of the cylindrical shaft for astigmatic patients, thus providing greater patient comfort and ease of adjustment; and (iv) the ability to provide lens designs that are finely adaptable to the individual needs of a patient.

In accordance with the teachings herein, the present invention provides a concentric, multi-focus annular ring lens for astigmatic presbiops, wherein one of the front and rear surfaces of the lens defines a central area, comprising a circular disc that has a spherical surface that corresponds to a remote optical power, of basic prescription. A plurality of annular rings surround the central area and comprise at least one annular ring of near, spherical optical power and at least one ring annular of optical power, spherical, which corresponds to the prescription of the cylindrical optical power of the patient, to provide visual acuity for astigmatic presbyopia. In greater detail, the annular ring of spherical optical power, which corresponds to the prescription of cylindrical optical power of the patient, may correspond to the prescription of full cylindrical power or a fraction of the prescription of full cylindrical power. The plurality of annular rings also comprises at least one annular ring of remote, spherical optical power. The plurality of annular rings may consist of annular rings of near optical power, spherical, annular rings of optical power at a distance and annular rings of alternating optical power, which corresponds to the prescription of the cylindrical optical power of the patient. The innermost annular ring is preferably an annular ring of near, spherical optical power and the second innermost annular ring can be an annular ring of spherical optical power, which corresponds to the prescription of cylindrical optical power of the patient and the third ring annular plus interior is an annular ring of remote optical power, spherical. Alternatively, the second innermost annular ring is an annular ring of remote, spherical optical power and the third innermost annular ring is an annular ring of spherical optical power, which corresponds to the prescription of cylindrical optical power of the patient. The lens may consist of a contact lens to be used on the cornea of the eye, such as a soft hydrogel contact lens or an intraocular lens. For a contact lens, the central area and the plurality of annular rings are preferably formed on the rear surface of the lens to minimize reflection and brightness problems. In addition, the widths of the individual annular rings may be different to generate a power profile, which varies to generate different optical power ratios at a distance to cylindrical correction optical power and near optical power.

BRIEF DESCRIPTION OF THE DRAWINGS The above objects and advantages of the present invention, for concentric lens designs for astigmatic presbiops, can be more readily understood by one skilled in the art, with reference being made to the following detailed description of several of its preferred embodiments, taken together with the accompanying drawings, in which like elements are designated by identical reference numerals in all the various views and in which: Figure 1 is a plan view of the rear surface of a designed embodiment of a preferred type of contact lens, according to the teachings of the present invention, which has a central area with a circular disc having a remote optical power, spherical Rx of basic prescription, surrounded by a plurality of ring of near optical power, spherical , concentric, annular rings of remote optical power, spherical, concentric and annular rings spherical res, which correspond to the prescription of cylindrical power of the patient.

DETAILED DESCRIPTION OF THE DRAWINGS The present invention provides a lens design for astigmatic presbiops. A presbiope requires a lens with a remote spherical prescription, basic to focus on distant objects and spherical prescription, close (added) to focus on nearby objects. In addition to this, an astigmatic presbiope requires an astigmatic correction, usually in the nature of a cylindrical prescription, which specifies both the cylindrical optical power and the cylindrical axis orientation. The present invention takes into account the cylindrical prescription in the design of the lens, but does not use a cylindrical optical surface. On the contrary, the present invention recognizes that the brain can discriminate effectively between competing images, separately, accepting an image in focus and rejecting an out-of-focus image. Accordingly, the present invention provides a portion of the lens with a spherical surface having the prescription of cylindrical optical power, or more preferably a fraction of the total cylindrical prescription and relies on the brain to discriminate and accept an image in focus to compensate for the patient's astigmatism. The spherical surface which corresponds to the cylindrical prescription, provides a lens with an improved depth of field for astigmatic little cylindrical. With reference to the drawings in detail, Figure 1 is a plan view of the rear surface of a designed embodiment of a preferred type of contact lens 10 according to the teachings of the present invention. The lens 10 has a central area with a circular disk 12 containing a remote optical power, spherical Rx of basic prescription, which is surrounded by a plurality of concentric, alternating annular rings 14, 16, 18, 20 and 22. The plurality of concentric, alternating annular rings includes an annular ring 14, of close optical power, spherical, annular rings 18 and 22, of remote optical power, spherical and annular rings 16 and 20 of spherical power, which correspond to the prescription of cylindrical power of the patient. The spherical power, which corresponds to the prescription of the cylindrical power of the patient can be the sum of the optical power at a distance, spherical, basic and the optical power of cylindrical prescription or the sum of the optical power at distance, spherical, basic and a portion (25% to 100%) of the optical power of cylindrical prescription. Preferably, the back surface of the lens is provided with the multiplicity of concentric rings shown in Figure 1, although the front surface is also suitable, particularly in intraocular lenses. For example, consider a presbyopic, astigmatic patient with a prescription of: -2.00 / -1.00 x 180 with 1.25D added. In this prescription -2.00 diopters is the description Rx of spherical distance, basic, -1.00 diopter is the prescription Rx correction of cylindrical, astigmatic optical power and 180 specifies a horizontal cylindrical axis and 1.25 diopters is the Rx prescription of near spherical prescription, added. In this exemplary mode, the powers chosen for the concentric annular rings can be SPHERE (S) = -2.00D (diopter), CYLINDER (C) = -3.00D (which is the sum of the spherical distance prescription Rx -2.00 and the cylinder prescription Rx of -1.00) and NEAR (N) = -0.75D (which is the sum of the spherical distance prescription Rx -2.00 and the spherical prescription, close Rx added of +1.25). Some patients may not require full aggregate and cylindrical powers in these designs. For these cases, the cylindrical and near powers can be made from a fraction (preferably 50%) of the aggregate power or of the complete cylinder. The cylindrical power can be the complete cylindrical difference of any portion thereof that is in the range of 25% to 100% of the full, refractive cylindrical power. The position specified for the cylindrical axis is ignored, since a spherical surface is replaced by it. It is not expected that the patient's visual acuity will deteriorate significantly for low cylindrical astigmatics due to the increased focus depth provided by the concentric annular ring designs of the present invention. Alternatively, the close, added optical power could be a non-constant function through the concentric annular rings. The present invention works by alternating the spherical power with the equivalent, cylindrical spherical power in such a way as to provide adequate levels of images of both optical powers for the observer's retina. In general, the powers in the zones can be arranged in a certain way so that it is adequate to the visual needs of the patient. Some examples of possible arrangements are shown in the following, in which the central disk 12 is listed as the first ring: % RINGS FOR DISPOSITION OF RINGS FROM THE CENTER OF THE LENS # OF RINGS SPHERE CLOSED CYLINDER SNCS 4 50 25 25 SNSCS 5 60 20 20 SNCSCNS 7 43 29 29 SNSCSNSCSNS 11 55 18 27 SNCNSNCNSNCNS 13 31 23 46 SNCNSCSCSNCNS 13 38 31 31 (where S = SPHERE, C = CYLINDER AND N = NEAR) In the alternative modalities, the positions of C and N can be inverted and obviously, many other combinations than those shown specific, are possible. The combined areas of the central spherical disc 12 and the surrounding annular rings 14 to 22 comprise the active optical area of the lens, which is surrounded by a lenticular (non-optic) area 24, which is bevelled on its outer circumference a an outer circumferential edge 26 of the lens.

The lens can be a contact lens for use on the cornea of the eye, such as a soft hydrogel contact lens or it can be an intraocular lens. The central area and plurality of annular rings are preferably formed on the back surface of a contact lens, to minimize reflection and brightness problems. The size of a person's pupil is a function, which is dependent on the intensity of the light and is an important parameter in the design of ophthalmic lenses, particularly contact lenses and intraocular lenses. In addition, the widths of the individual annular rings may be different, to adjust the area of the optical zone dedicated to each power, to generate a power profile, which varies to generate different ratios of the optical power of distance to the cylindrical correction and the near optical power. In addition, to provide a depth of focus effect, it can incorporate the asphericity in either the S, C and / or N rings, or the surface that does not contain the concentric rings can become aspheric. In addition, in vivo image quality measurement devices can be used to optimize ocular image quality in concentric annular ring lens designs to produce even more improved designs. This is done using an in vivo image quality measurement device to measure and decrease the aberration amounts of a first design of a lens in the patient's eye to measure residual aberrations and then redesign the lens to reduce aberrations residual measures and improve visual acuity and functioning. The redesign of the lens may include the aspherization of the surface opposite the surface defining the central area and the plurality of annular rings, or aspherization of the surface of the concentric ring annulus. An aberroscope or MTF point extension device is preferably used to measure the modulation transfer function of the combination of the lens and the eye. Obviously, many different embodiments of the present invention are possible, with alterations in the number of annular rings, the widths and arrangements of the annular rings and the optical powers assigned to each of the annular rings. Although various embodiments and variations of the present invention for annular ring lens designs, concentric for astigmatic presbiops are described in detail herein, it should be apparent that the description and teachings of the present invention will suggest many alternative designs for those with skill in the technique.

Claims

NOVELTY OF THE INVENTION CLAIMS

1. An annular ring lens, concentric, multiple focus for astigmatic presbiops, characterized in that it comprises: a. the lens having a front surface and an opposite rear surface, wherein one of the front and rear surfaces defines a central area, comprising a circular disk having a surface corresponding to a remote optical power, of basic prescription; and b. a plurality of annular rings surrounding the central area and comprising at least one annular ring of near optical power and at least one annular ring of optical power which corresponds to the cylindrical optical power of the patient's prescription, to provide sharpness visual for astigmatic presbyopia.

2. The concentric ring lens with multiple focus for astigmatic presbiops according to claim 1, characterized in that the circular disk defines a spherical curve.

3. The concentric ring lens with multiple focus for astigmatic presbiops according to claim 2, characterized in that the annular rings define spherical curves.

4. The concentric ring lens with multiple focus for astigmatic presbiops, according to claim 1, characterized in that the circular disk defines an aspheric curve.

5. The concentric ring lens with multiple focus for astigmatic presbiops, according to claim 4, characterized in that the annular rings define aspheric curves.

6. The concentric annular ring lens, of multiple focus for astigmatic presbiops according to claim 3, characterized in that the annular ring of spherical optical power, which corresponds to the cylindrical optical power of prescription of the patient, corresponds to the prescription of the power full cylindrical

7. The concentric annular ring lens, of multiple focus for astigmatic presbiops according to claim 3, characterized in that the annular ring of spherical optical power, which corresponds to the prescription of cylindrical optical power of the patient, corresponds to a fraction of the prescription of full cylindrical power.

8. The concentric annular ring lens of multiple focus for astigmatic presbiops according to claim 3, characterized in that the plurality of annular rings also comprise at least one annular ring of optical, remote, spherical power.

9. The multi-focus, concentric annular ring lens for astigmatic presbiops according to claim 3, characterized in that the plurality of annular rings comprise annular rings of near optical power, spherical, annular rings of remote optical power, spherical and annular rings of optical power spherical, which correspond to the prescription of cylindrical optical power of the patient.

10. The concentric annular ring lens, of multiple focus, for astigmatic presbiops according to claim 3, characterized in that the innermost annular ring is an annular ring of near optical power, of spherical prescription and the second innermost annular ring is a ring Spherical optical power ring, which corresponds to the prescription of cylindrical optical power of the patient.

11. The multi-focus, concentric annular ring lens for astigmatic presbiops according to claim 10, characterized in that the innermost annular ring is an annular ring of spherical, remote optical power.

12. The concentric annular ring lens of multiple focus for astigmatic presbiops according to claim 3, characterized in that the innermost annular ring is an annular ring of near optical power, of spherical prescription and the second innermost annular ring is an annular ring of remote optical power, spherical.

13. The concentric annular ring lens, of multiple focus for astigmatic presbiops according to claim 12, characterized in that the third innermost annular ring is an annular ring of spherical optical power, which corresponds to the prescription of cylindrical optical power of the patient.

14. The concentric ring lens of multiple focus for astigmatic presbiops according to claim 3, characterized in that the lens comprises a contact lens to be used on the cornea of the eye.

15. The concentric ring lens of multiple focus for astigmatic presbiops according to claim 14, characterized in that the contact lens comprises a soft hydrogel contact lens.

16. The concentric ring lens of multiple focus for astigmatic presbiops according to claim 3, characterized in that the lens comprises an intraocular lens.

17. A multi-focus, concentric annular ring lens for astigmatic presbiops according to claim 3, characterized in that the widths of the individual annular rings are different to generate a power profile, which varies to generate different ratios of optical power to power of cylindrical correction and near optical power.

18. A multi-focus, concentric annular ring lens for astigmatic presbiops according to claim 3, characterized in that the central area and the plurality of annular rings are formed on the back surface of the lens, to minimize reflection and brightness.

19. The concentric annular ring lens with multiple focus for astigmatic presbiops according to claim 3, characterized in that the other one of the posterior front surfaces comprises an aspheric reinforcement curve.

20. A method for designing a concentric, multi-focus annular ring lens for astigmatic presbiops, characterized in that it comprises: a. the lens has a front surface and an opposite rear surface, wherein one of the front and rear surfaces defines a central area comprising a circular disk having a surface corresponding to a remote optical power of basic prescription; b. a plurality of annular rings surrounding the central area and comprising at least one annular ring of near optical power and at least one annular ring of optical power, which corresponds to the prescription of optical, cylindrical power of the patient, to provide visual acuity for astigmatic presbyopia; c. perform an in vivo image quality analysis, with an in vivo quality analysis instrument, of the lens over the eye to measure any of the residual aberrations; d. reduce residual aberrations by redesigning the lens to improve visual acuity and performance.

21. The method for designing a single vision, concentric ring ring lens according to claim 20, characterized in that the redesign of the lens includes sputtering the surface opposite the surface defining the central area and the plurality of annular rings. DESIGN OF CONCENTRIC ANULAR RING LENS FOR ASTIGMATIC PRESBIOPS SUMMARY OF THE INVENTION Concentric lens designs for 5 astigmatic prespipes are described, which comprises at least one surface which has a circular central portion and a plurality of concentric annular rings with at least three separate optical powers, corresponding to a prescription for a patient and that correspond to 1) a 0 spherical prescription Rx, basic distance Rx, 2) an added spherical prescription, close Rx and 3) a spherical prescription that corresponds to the total, or preferably a fraction of the cylinder prescription Rx. An astigmatic presbyopic prescription contains an astigmatic correction 5, usually in the nature of a cylindrical prescription, which specifies both the cylindrical optical power and the cylindrical axis orientation. The cylindrical prescription is taken into account in the design of the lens, but not with an optical or cylindrical surface. On the contrary, the present invention recognizes that the brain can effectively discriminate between competing images separately by accepting an image in focus and rejecting an out-of-focus image. Accordingly, a portion of the lens is provided with a spherical surface corresponding to the cylindrical prescription, or more preferably a fraction of the full cylindrical prescription and the brain is based to discriminate and accept an image in focus to compensate for the astigmatism of the lens. patient.