Intraocular lens with multiple spiral zones

Abstract

An intraocular lens the optical power map of which comprises at least one spiral track. There are at least a first and a second cross section of the spiral track the dioptric range of each of which is at least 0.5 dioptre. The average optical power of the first cross section is at least 0.5 dioptre apart from the average optical power of the second cross section.

Description

[0001] Intraocular lens with multiple spiral zones

[0002] Description

[0003] Field of the invention

[0004] The invention relates to an intraocular lens.

[0005] Background of the invention

[0006] US 5198844 A discloses a multifocal refractive lens that comprises of a plurality of segments of alternating optical power for distance vision and for near vision. The segments are divided by an arcuate path going from the centre of the lens to edge.

[0007] From US 5408281 A, a multifocal ophthalmic contact lens with a spiral-like pattern is known. The spiral bands originate from the centre of the lens and thus from the optical axis. Different dioptric powers are created by choosing a cross-sectional band profile capable of selectively alternating the angle of impact of light rays on the eye. The band can for example provide a continuous and progressive range of powers or a discrete set of individual powers.

[0008] US 20030117577 A1 discloses a bifocal ophthalmic lens with an area of distance optical power within which, in a substantially spiral pattern, an area (12) of near optical power is interspersed.

[0009] In WO 2020260679 A1 , an optical device is discussed a surface of which has two meridians and at least one portion of which forms, seen face-on, spiral segments to produce a focus that extends over a tubular region.

[0010] WO 2022183258 A1 discloses an intraocular lens that comprises a base topology that is supplemented with an additional power distribution along spiral tracks. For this, the surface is shifted axially in a step-like helicoidal pattern following the internal and external edges of the spiral tracks, and transition regions are introduced between the shifted zones. From US 20230393481 A1 , a multifocal ophthalmic lens is known where surface power map of a lens surface or a lens power map, which is the combination of the surface power maps comprises a spiral. Moreover, ophthalmic lenses for myopia control that have power maps comprising spirals are known from US 20210341752 A1 and US 20230125705 A1.

[0011] Object of the invention

[0012] It is an object of the present invention to provide an improved intraocular lens.

[0013] Solution according to the invention

[0014] In the following, any reference to one (including the articles “a” and “the”), two or another number of objects is, provided nothing else is expressly mentioned, meant to be understood as not excluding the presence of further such objects in the invention. The reference numerals in the patent claims are not meant to be limiting but merely serve to improve readability of the claims.

[0015] According to the invention, the problem is solved by an intraocular lens with the features of claim 1. The optical power map of the intraocular lens comprises at least one spiral track. There are at least a first and a second cross section of the spiral track the dioptric range of at least one, preferably each, of which is at least 0.5 dioptre, wherein the average optical power of the first cross section is at least 0.1 dioptre apart from the average optical power of the second cross section.

[0016] It is achievable advantage of the intraocular lens according to the invention that due to the dioptric ranges of the cross sections, a focus created by the spiral track can be elongated along the direction of the optical axis, resulting in an improved focal depth. Moreover, it is achievable that with the two cross sections of different average optical power, two elongated focal areas are produced. This may for example be an elongated focus ranging from far vision to intermediate vision, and another elongated focus ranging from intermediate vision to near vision. Accordingly, with the invention an intraocular lens can be obtained that provides vision across multiple visual distance intervals or even the entire natural interval of visual distance from near vision to far vision. The term “optical power map” as used herein refers to the distribution of optical power across a plane of the lens perpendicular to the optical axis. In particular, the profiles of the surfaces of the lens as well as the refractive index of the lens and possible variations of the refractive index across the lens can contribute to the power map.

[0017] In the context of the present invention, a “spiral track” is an elongated area of the power map that extends along a spiral path from a location on the surface of the lens closer to the centre of the lens to a location on the surface of the lens closer to the outer edge of the lens, and that, in the cross section at any position along the spiral path, has an optical power profile with one maximum and one minimum. A “spiral path” is a path that progresses simultaneously and monotonously in both azimuthal and radial direction of the lens. The spiral path can progress in an azimuthal direction either clockwise or counterclockwise - when looking onto the lens surface - as tit progresses in the radial direction from a location closer to the centre of the lens to a location closer to the outer edge of the lens. In the context of the present invention, the “cross section” of a spiral track extends perpendicularly to the spiral path and spans the width of the spiral path. The power profile of the cross section of the spiral track having a maximum and a minimum can contribute to the elongation of the spiral zone’s focus along the optical axis.

[0018] In the context of the present invention, the “dioptric range” of a cross section of a spiral track is the difference between the maximum optical power of the power profile of the cross section and the minimum optical power of the power profile of the cross section. The “maximum” optical power of the power profile of the cross section is defined as the average of the contiguous 10% along the width of the spiral track that have the maximum optical power. Similarly, the “minimum” optical power of the power profile of the cross section is defined as the average of the contiguous 10% along the width of the spiral track that have the maximum optical power. This definition of maxima and minima serves to render the definition of the “dioptric range” relevant even in a situation where, for example due to artifacts or manufacturing requirements, there are very small areas of excessive variation in optical power. The “width” of the spiral track is defined as starting at the midpoint between the minimum of the cross section and the closest maximum of an adjacent cross section of the same or another (in the case of multiple spiral tracks) spiral track and ending at the midpoint between the maximum of the cross section and the closest minimum of an adjacent cross section of the same or another (in the case of multiple spiral tracks) spiral track. This definition is to avoid arbitrariness with regard to the limits of the cross section of the spiral arm. Two cross sections are “adjacent” if they extend along a common continuous line and there is no other cross section - of the same or another spiral track - between the two cross sections on the common continuous line. In the context of the definition of “adjacent” and “neighbouring” (see further below) “continuous line” means that the line is a continuous succession of cross sections. Note that due to the inherent inclination of a spiral path, the continuous line typically will not coincide with a radius of the power map. Yet, if the spiral is centred around the apex of the lens, the continuous line approaches a radius of the power map the tighter the spiral is, ie the closer a turn of the spiral path approaches a circular line.

[0019] In the context of the present invention, the term “average optical power” of a cross section refers to the average of the optical power across the width of the cross section.

[0020] Preferred embodiments of the invention

[0021] Preferred features of the invention which may be applied alone or in combination are discussed in the following and in the dependent claims.

[0022] The preferred intraocular lens comprises a spiral zone. As used herein, the term ““spiral zone” refers to an area of the optical power map of the lens across which at least one spiral track extends. The spiral track may extend further, preferably beyond one or two edges of the spiral zone. Preferably, the first and the second cross section are within the spiral zone. Preferably, the average optical power of all cross sections of the spiral track within the spiral zone is at least 0.5 dioptre.

[0023] In a preferred embodiment of the invention, the average optical power of the first cross section of the spiral track and / or the average optical power of the second cross section of the spiral track, more preferably of all cross section within the spiral zone, are at least 0.1 D, more preferably at least 0. 5 D (dioptre), more preferably at least 1 D, even more preferably at least 1.5 D, 2 D, 2.5 D, 3 D, 3.5 D, 4 D, 4.5 or 5 D apart, for example 6 D apart. A large separation of the zones allows for a broad interval of visual distance to be realised with the lens according to the invention. Some embodiments of the invention comprise more than two spiral tracks. For example, in certain embodiments of the invention there are two, three, four or five spiral tracks.

[0024] Preferably, these spiral tracks are parallel spiral tracks.

[0025] Preferably, in two, three, four, five or six of the spiral tracks, more preferably in all spiral tracks, there are at least a first and a second cross section of the spiral track, more preferably of all cross section within the spiral zone, the average optical power of the first cross section being at least 0.1 D, more preferably at least 0.5 D, more preferably at least 0.75 D, even more preferably at least 1.0 D, 1.5 D, 2 D, 2.5 D, 3 D, 3.5 D, 4 D, 4.5 or 5 D, for example 6 D apart from the average optical power of the second cross section the average optical power of each of these spiral tracks.

[0026] In a preferred embodiment of the invention, the dioptric ranges of the first and the second cross section of the spiral track, more preferably all cross sections of the spiral track in the spiral zone, are at least 0.25 D, more preferably at least 0.5 D, even more preferably at least 1 D, 1.5 D, 2 D, 2.5 D, 3 D, 3.5 D or 4 D, for example 6 D. With a greater the dioptric range of a cross section, the more elongated focus can be achieved, providing improved focal depth.

[0027] In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, more preferably in all spiral tracks, the dioptric ranges of the first and the second cross section of the spiral track, more preferably all cross sections of the spiral track in the spiral zone, are at least 0.25 D, more preferably at least 0.5 D, even more preferably at least 1 D, 1.5 D, 2 D, 2.5 D, 3 D, 3.5 D or 4 D, for example 6 D.

[0028] In a preferred embodiment of the invention within the spiral zone, preferably even along the entire spiral track, there are no two cross sections along the spiral track the average optical power of which are more than 16 D, more preferably not more than 15 D, even more preferably not more than 14 D, 13 D, 12 D, 11 D, 10 D, 9 D, 8 D, 7 D or 6 D apart. With this embodiment of the invention, it can be achieved that the optical powers of the two zones are sufficiently close to avoid a gap in vision at the intermediate distances.

[0029] In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks or in all spiral tracks, at least within the spiral zone, preferably even along the entire spiral track, there are no two cross sections along the same spiral track the average optical power of which are more than 16 D, more preferably not more than 15 D, even more preferably not more than 14 D, 13 D, 12 D, 11 D, 10 D, 9 D, 8 D, 7 D or 6 D apart.

[0030] In a preferred embodiment of the invention, the overlap of the dioptric range of a cross section of the spiral track which cross section has maximum average optical power with a cross section of the spiral track which cross section has minimum average optical power is less than 2 D, more preferably less than 1.75 D, even more preferably less than 1.5 D, 1 D, 0.75 D, 0.5 D or 0.25 D. Particularly preferably, the dioptric range of a cross section of the spiral track with maximum average optical power does not overlap with a cross section of the spiral track with minimum average optical power. By minimizing or even avoiding the overlap between the cross sections, it can be prevented that the elongation of the one or more of the spiral zones along the optical axis is unnecessarily large. A large elongation can entail an undue amount of spreading of the focus in the focal plane and thus a reduction in definition of the image on the retina. *

[0031] In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, preferably even along the entire spiral track, the overlap of the dioptric range of a cross section of the spiral track with maximum average optical power with a cross section of the same spiral track with minimum average optical power is less than 2 D, more preferably less than 1.75 D, even more preferably less than 1.5 D, 1 D, 0.75 D, 0.5 D or 0.25 D. Particularly preferably, the dioptric range of a cross section of the spiral track with maximum average optical power does not overlap with a cross section of the same spiral track with minimum average optical power.

[0032] The first and the second cross section of a preferred spiral track, preferably all cross sections at least within the spiral zone, more preferably along the entire track, have an average optical power within an interval that starts at 0 D, more preferably at 0.5 D, even more preferably at 1 D, even more preferably at 18 D, even more preferably 18.5 D, even more preferably 19 D, and ends at 37 D, more preferably 36 D, even more preferably 25 D, even more preferably 24.5 D, even more preferably 24 D. In a preferred embodiment of the invention, a cross section of the spiral track with minimum average optical power at least within the spiral zone, more preferably along the entire track, has an average optical power in an interval range that starts at 0 D, more preferably at 0.5 D, even more preferably at 1 D, even more preferably at 18 D, even more preferably 18.5 D, even more preferably 19 D, and ends at 37 D, more preferably 36 D, even more preferably 23 D, even more preferably 22.5 D, even more preferably 22 D. In a preferred embodiment of the invention, a cross section of the spiral track with maximum average optical power at least within the spiral zone, more preferably along the entire track, has an average optical power in a range that starts at 2D, more preferably 2.5 D, even more preferably 3 D, even more preferably 21 D, more preferably 21.5 D, even more preferably 22 D, and ends at 37 D, more preferably 36.5 D, even more preferably 36 D, even more preferably 25 D, more preferably 24.5 D, even more preferably 24 D.

[0033] In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks or in all spiral tracks, the first and the second cross section of the spiral track, preferably all cross sections at least within the spiral zone, more preferably along the entire track, have an average optical power within an interval that starts at 0 D, more preferably at 0.5 D, even more preferably at 1 D, even more preferably at 18 D, even more preferably 18.5 D, even more preferably 19 D, and ends at 34 D, more preferably 33.5 D, more preferably 33 D, more preferably 25 D, more preferably 24.5 D, even more preferably 24 D. Preferably in two, three, four, five or six of the spiral tracks or in all spiral tracks, a cross section of the spiral track with minimum average optical power at least within the spiral zone, more preferably along the entire track, has an average optical power in an interval range that starts at 0 D, more preferably at 0.5 D, even more preferably at 1 D, even more preferably at 18 D, even more preferably 18.5 D, even more preferably 19 D, and ends at 23 D, more preferably 22.5 D, even more preferably 22 D. Preferably in two, three, four, five or six of the spiral tracks or in all spiral tracks, a cross section of the spiral track with maximum average optical power at least within the spiral zone, more preferably along the entire track, has an average optical power in a range that starts at 21 D, more preferably 21.5 D, even more preferably 22 D, and ends at 37 D, more preferably 36.5 D, more preferably 36 D, more preferably 25 D, more preferably 24.5 D, even more preferably 24 D.

[0034] At least within the spiral zone, more preferably along the entire track, the change in the average optical power between any cross section of a preferred spiral track and any cross section of this same preferred spiral track that is neighbouring the former cross section is less than 20 D, more preferably less than 15 D, more preferably less than 12 D, more preferably less than 10 D, more preferably less than 8 D, even more preferably less than 6 D. In the context of the present invention, two cross sections of the same spiral track are referred to as “neighbouring” if they lie on a common continuous line and there is no other cross section of the same spiral track between the two cross sections on the common continuous line (note however that, if there are multiple spiral tracks, there may be a cross section of another spiral track between the two cross sections on the common continuous line; in this regard, the term “neighbouring” differs from the term “adjacent” as used herein). This embodiment of the invention can provide for a smooth change in average optical power. It is an achievable advantage of such smoothness, that optical artifacts can be avoided. The continuous line is defined in the same way as in the context of the definition further above of an adjacent cross section.

[0035] In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks or in all spiral tracks, at least within the spiral zone, more preferably along the entire track, the change in the average optical power between any cross section of a preferred spiral track and any adjacent cross section of another spiral track is less than 20 D, more preferably less than 15 D, more preferably less than 12 D, more preferably less than 10 D, more preferably less than 8 D, even more preferably less than 6 D.

[0036] In a preferred embodiment of the invention, there is no cross section, at least within the spiral zone, more preferably along the entire track, the dioptric range of which is more than 12 D, more preferably more than 11 D, even more preferably more than 10 D, 9 D, 8 D, 7 D, 6 D or 5 D. A smaller dioptric range can provide for less spreading of the focus in the focal plane and thus a better definition of the image on the retina.

[0037] In a preferred embodiment of the invention, the spiral zone covers a surface area of the lens of at least 0.8 mm2(square millimetres), more preferably 1.6 mm2, 3.2 mm2,

[0038] 4.8 mm2, 6.4 mm2, of the lens. Thereby, advantageously, it can be assured that sufficient an amount of light is focussed into the focus of the zone to provide for a sufficiently bright image. When in the context of the present invention reference is made to measure of the “surface area of the lens”, this surface area is meant to be the measure of a projection of the lens surface in the direction of the optical axis on a plane that extends perpendicularly to the optical axis.

[0039] In a preferred embodiment of the invention, the spiral zone is ring-shaped. The ring of the spiral zones has a circular inner and / or outer edge. The edges of the inner and outer edges preferably are concentric, ie, the zone is annular. The preferred annular spiral zone is at least 200 pm (micrometres), more preferably 300 pm, even more preferably 400 pm, 500 pm, 600 m or 700 pm wide. The width is measured from the innermost edge to the outermost edge of the annular spiral zone. The preferred annular spiral zone is less than 2 mm (millimetres), more preferably less than 1.5 mm, even more preferably less than 1 mm, 900 pm, 800 pm or 700 pm wide.

[0040] To avoid optical artefacts, the spiral(s) tracks must neither be too narrow nor too wide. The width of the spiral track(s) can be expressed in terms of the pitch. As used herein, the term “pitch” refers to the spacing between adjacent spiral track sections in an analogy to the definition of the pitch of the thread of a screw. It is measured between adjacent spiral track sections in the radial direction of the lens in a projection of the lens surface, which projection is in the direction of the optical axis on a plane that extends perpendicularly to the optical axis of the lens. Preferably, at least in the spiral zone, more preferably even along the entire spiral track, the pitch of the spiral track, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or greater than 10 pm (micrometres), more preferably equal to or greater than 20 pm, even more preferably equal to or greater than 30 pm, 40 pm or 50 pm. In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, more preferably even along the entire spiral track, the pitch of the spiral track, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or greater than 10 pm (micrometres), more preferably equal to or greater than 20 pm, even more preferably equal to or greater than 30 pm, 40 pm or 50 pm.

[0041] Preferably, at least within the spiral zone, more preferably even along the entire spiral track, the pitch of the spiral track, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or less than 400 pm (micrometres), more preferably equal to or less than 360 pm, even more preferably equal to or less than 320 pm, 280 pm or 240 pm. In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, more preferably even along the entire spiral track, the pitch of the spiral track, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or less than 700 pm (micrometres), more preferably equal to or less than 360 pm, even more preferably equal to or less than 320 pm, 280 pm or 240 pm.

[0042] As in a spiral zone the spiral track progresses from location on the surface of the lens closer to the centre of the lens to a location on the surface of the lens closer to the outer edge of the lens, at least within the spiral zone, more preferably even along the entire spiral track, the pitch between adjacent spiral track sections may increase, decrease or remain constant. In some embodiments of the invention, at least within the spiral zone, more preferably even along the entire spiral track, the pitch, measured in the radial direction of the lens, between adjacent spiral track sections increases from a location on the surface of the lens closer to the centre of the lens to a location on the surface of the lens closer to the outer edge of the lens by at least 5 %, more preferably by at least 10 %, even more preferably by at least 15 %, 20 % or 25 %.

[0043] In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, more preferably even along the entire spiral track, the pitch between adjacent spiral track sections may increase, decrease or remain constant. Preferably in the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, more preferably even along the entire spiral track, the pitch measured in the radial direction of the lens, between adjacent spiral track sections increases from a location on the surface of the lens closer to the centre of the lens to a location on the surface of the lens closer to the outer edge of the lens by at least 5 %, more preferably by at least 10 %, even more preferably by at least 15 %, 20 % or 25 %.

[0044] Alternatively, at least within the spiral zone, more preferably even along the entire spiral track, the pitch, measured in the radial direction of the lens, between adjacent spiral track sections decreases from a location on the surface of the lens closer to the centre of the lens to a location on the surface of the lens closer to the outer edge of the lens by at least 5 %, more preferably by at least 10 %, even more preferably by at least 15 %, 20 % or 25 %. Preferably in the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, more preferably even along the entire spiral track, the pitch measured in the radial direction of the lens, between adjacent spiral track sections decreases from location on the surface of the lens closer to the centre of the lens to a location on the surface of the lens closer to the outer edge of the lens by at least 5 %, more preferably by at least 10 %, even more preferably by at least 15 %, 20 % or 25 %.

[0045] If the pitch of the spiral track increases or decreases, such increase or decrease preferably is smooth, more preferably approximately linear. Preferably in the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, the increase or decrease is smooth, more preferably approximately linear.

[0046] In a fashion similar to a multi-start screw, a spiral zone may have multiple parallel spiral tracks. Preferably, at least in the spiral zone, preferably along the entire length of the spiral tracks, the number of tracks is one or more, for example 2 or 3. Preferably, the number of tracks is six or less, for example 5 or 4.

[0047] The steepness of a spiral track, ie how rapidly it progresses from the centre or the inner edge of the spiral zone to the zone’s outer edge can be expressed in term of the spiral track’s lead. As used herein, the term “lead” refers to the spacing between the nearest spiral track sections of the same spiral track in an analogy to the definition of the lead of the thread of a screw. It is measured in the radial direction of the lens in a projection of the lens surface, which projection is in the direction of the optical axis on a plane that extends perpendicularly to the optical axis of the lens. The pitch and the lead of the spiral zone is related via the number of parallel spiral tracks as the leads essentially is the pitch times the number of spiral tracks. Preferably, at least in the spiral zone, more preferably even along the entire spiral track, the lead, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or greater than 10 pm (micrometres), more preferably equal to or greater than 20 pm, even more preferably equal to or greater than 30 pm, 40 pm or 50 pm.

[0048] In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, more preferably even along the entire spiral track, the lead, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or greater than 10 pm (micrometres), more preferably equal to or greater than 20 pm, even more preferably equal to or greater than 30 pm, 40 pm or 50 pm.

[0049] Preferably, at least in the spiral zone, more preferably even along the entire spiral track, the lead, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or less than 2000 pm (micrometres), more preferably equal to or less than 1500 pm, even more preferably equal to or less than 1 100 pm, 900 pm, 700 pm or 500 pm. By keeping the lead small, it can be avoided that in the focal plane, the light is to an undue degree focussed off the optical axis, which may result in a reduction in definition of the image on the retina. In the case of a lens with multiple spiral tracks, preferably, in two, three, four, five or six of the spiral tracks, preferably in all spiral tracks, at least within the spiral zone, more preferably even along the entire spiral track, the lead, between adjacent spiral track sections is equal to or less than 1500 pm (micrometres), more preferably equal to or less than 1300 pm, even more preferably equal to or less than 1 100 pm, 900 pm, 700 pm or 500 pm.

[0050] The inventors have found that particularly favourable results can be achieve with an intraocular lens that combines the spiral zones with at least one non-spiral zone. In the context of the present invention, a “non-spiral zone” is defined by not comprising any spiral tracks. Preferably, it the non-spiral zone is axisymmetrical about the optical axis if the lens. Particularly preferably it has the properties of a spherical or aspherical lens.

[0051] A preferred non-spiral zone has an average dioptre in a range that starts at 0 D, more preferably 0.5 D, even more preferably 1 D, more preferably 18 D, more preferably 18.5 D, even more preferably 19 D, and ends at 27 D, more preferably 36.5 D, more preferably 36 D, more preferably 25 D, more preferably 24.5 D, even mor preferably 24 D. A preferred non- spiral zone covers a surface area of the lens of at least 0.3 mm2, more preferably 0.4 mm2, 0.5 mm2, 0.6 mm2, 0.7 mm2, of the lens.

[0052] The preferred non-spiral zone does not have a hole, ie, it is in particular not ring-shaped. More preferably, the non-spherical zone has the shape of a full circle. It preferably is located at the centre of the lens. Particularly preferably it is concentric with the spiral zone. Yet, the invention also encompasses embodiments in which the non-spiral zone is ring-shaped. Preferably, the non-spiral zone at the centre of the lens has a radius of more than 50 pm, more preferably more than 100 pm, even more preferably more than 250 pm, for example 400 pm. Preferably, the non-spiral zone at the centre of the lens has a radius of less than 1500 pm, more preferably less than 1300 pm, even more preferably more than 1000 pm. The radius is meant to be measured in a projection of the lens surface, which projection is in the direction of the optical axis on a plane that extends perpendicularly to the optical axis of the lens.

[0053] The invention also encompasses embodiments in which there is more than one non-spiral zone, for example a non-spiral zone without a hole, and another, ring shaped non spherical zone. In particular, a preferred lens comprises a non-spiral peripheral zone, which surrounds all other zones. In some embodiments of the invention, this peripheral zone has no optical power at all. In this case, the peripheral zone mainly serves to hold the lenses haptics for maintaining the lens in its position in the eye, for example in the capsular sac.

[0054] Preferably, between a non-spiral zone and the spiral zone there is a transition zone. In a preferred transition zone, spiral tracks(s) gradually take shape or disappear. The preferred transition zone is on one side adjacent to the non-spiral zone, and on the other side adjacent to the spiral zone. It is preferred that the non-spiral zone is adjacent to one or more spiral zones. As used herein, the term “adjacent” with regard to zones is meant to express that the other edge of one of the adjacent zones coincides with the inner edge of the other adjacent zone. A preferred transition zone is essentially annular. Preferably, the transition zone from its inner edge to its outer edge is more than 10 pm, more preferably more than 20 pm, even more preferably more than 30 pm, 40 pm, 50 pm, 60 pm, 80 pm. for example 100 pm wide. A preferred transition zone from its inner edge to its outer edge is less than 500 pm, more preferably less than 400 pm, even more preferably less than 300 pm or 200 pm wide.

[0055] A particularly preferred lens comprises a non-spiral zone at the centre of the lens, which non spiral zone is essentially circular. The non-spiral zone preferably is followed by an adjacent, essentially annular transition zone, followed by an adjacent, essentially annular spiral zone. The spiral zone preferably is followed by an adjacent, essentially annular second transition zone, followed by an annular non-spiral peripheral zone.

[0056] Brief description of the drawings

[0057] In the following, further preferred embodiments of invention are illustrated by means of examples. The invention is not limited to these examples, however.

[0058] The drawings schematically show:

[0059] Figure 1 Shows an increase in the depth of focus for an embodiment of the invention (green) compared to a standard monofocal intraocular lens (orange); Figure 2 Shows the geometrical dimensions and layout of the optical surface of the embodiment of the invention of Figure 1;

[0060] Figure 3 shows the optical power map of the lens that produces the defocus curves shown in Figure 1 with geometry of Figure 2;

[0061] Figure 4 Shows the optical power of the lens of Figures 1 to 3 along a radius of the lens; and

[0062] Figure 5 Shows the optical power of the lens of Figures 1 to 4 along a common continuous line of adjacent cross sections.

[0063] Detailed description of an embodiment of the invention

[0064] In the following description of preferred embodiments of the invention, identical reference numerals refer to identical or similar components.

[0065] An ideal intraocular lens (IOL) would have diffraction limited imaging performance and allow the eye to image objects from infinity to approximately 300 mm from the eye (the latter being closers to the eye than average reading distance). To achieve this, the lens has to be provided with either an adjustable focal length - lust like the natural lens of the eye - or with a depth of focus (DoF) that enables rays from infinity (ie, parallel rays entering the cornea) and rays from objects 300 mm from the eye (ie, diverging rays entering the cornea) to be simultaneously focused on the retina. The lens according to the present example of the invention uses this second approach, ie, it aims at approximating an ideal lens by providing the lens with an improved DoF. Such approach inevitably requires a compromise between a good imaging performance and useful range of vision, from far objects to objects getting nearer the eye, due to an appropriate DoF.

[0066] It can be seen in Figure 1, with the present invention the DoF can be markedly increase, resulting in a considerably enlarged range of vision as compared to that of a standard monofocal lens, while maintaining a good imaging performance across this range. In Figure 3, lens according to the invention is shown in green which the standard monofocal lens is shown in orange. The imaging quality is measured in terms of the simulated visual acuity as measured in log (MAR). Values above the dotted line are acceptable.

[0067] In Figure 1, the simulated visual acuity is plotted against defocus power (“Add (D)”) for two cases, a 3 mm pupil and a 4.5 mm pupil. Decreasing defocus power represents objects closer to the eye. A value of -2.5 D Add Cornea corresponds to an object that is approximately 400 mm from the eye; a value of 0.0 D corresponds to an object at infinity - for practical purposes, any object further than about 6 m from the eye can be considered to be at infinity. Both in the case of a 3 mm pupil (left hand side of the Figure 1) and in the case of a 4.5 mm pupil (right hand side of the Figure, 1) the range in which the simulated visual acuity is above the dotted line is considerably enlarged.

[0068] The geometric dimensions of the lens from which the simulated visual acuity plots of Figure 1 were obtained in shown in Figure 2. An aspheric lens surface is provided with an annular spiral zone. The inner diameter of the annular spiral zone is 2.2 mm, its outer diameter is 3.6 mm. Outside the spiral zone, the lens surface retains the conventional properties of an aspheric lens surface.

[0069] The spiral zone comprises two identical, adjacent spiral tracks that start out on opposite sides of the inner edge of the spiral zone. Each spiral track comprises five turns and progresses clockwise - when looking onto the lens surface - in an azimuthal direction as it progresses in the radial direction from the inner edge to the outer edge of the spiral zone.

[0070] Figure 3 shows the optical power map of the lens of Figure 2 over a 4.5 mm aperture. More precisely, the power map shown in figure 3 is a mirror image of the power map that would be observed when looking onto the lens surface; this can be seen from the fact that in Figure 3 the optical tracks appear to progress counterclockwise. The values “1.0” and “-1.0” on the axis in Figure 3 correspond to a lens radius of 2.25 mm. The colours in Figure 3 represent the optical power as shown in the colour bar on the right, the values are in dioptre and range from 20.5 dioptre (dark blue) to 33.7 dioptre (dark red).

[0071] The distribution of the optical power along a radius of the power map that extends from the centre of the lens towards its edge is shown in Figure 4 as a function of the radius. The apparent drop near the centre of the lens is the result of an inaccuracy in the simulation method used to obtain Figure 4. Similarly, Figure 5 shows the optical power of the lens along a common continuous line of adjacent cross sections of the spiral paths. Due to the inherent inclination of a spiral path, the continuous line does not coincide with a radius of the power map but is slightly tilted vis-a-vis the nearest radius. Each cross section comprises a minimum and a maximum of the optical power. One exemplary cross section extends between the dotted lines in Figure 5. As the lens comprises two spiral tracks, cross sections of the first and the second spiral track alternate in Figure 5.

[0072] The lens surface is obtained starting out from the power map shown in Figures 3 to 5 by exploiting that at any point of the power map the optical power (Ds) is related to the surface radius(r) of the lens required to obtain such optical power by the formula

[0073] Ds= (ni - na) / r

[0074] In this formula, ni is the refractive index of the surface material (ie, the lens material), and nais the refractive index of the medium (ie, the aqueous humour) in contact with the lens surface.

[0075] Therefore, rcan be easily computed if Dsis known: r = (ni-na) / Ds

[0076] As an example, if we assume the IOL is approximately equi-bi-convex, having approximately the same power on both the anterior and posterior surface, a 20.0 D lens would have 10.0 D on each surface.

[0077] If ni = 1.462 and na= 1.366, for +10.0 D surface power the local surface radius would be: r= (1.462-1.336) / 10 = 0.0126 m = 12.6 mm.

[0078] Working from the centre of the power map at a constant angle (meridian) the surface radius is computed from the local power according to the power map and corresponding surface sag is generated. This process can be repeated at multiple angles (eg every 1 degree) around the power map and a complete matrix of surface sag vs radial position and angle is thus generated. From which a real surface is manufactured. A similar approach could be used if the refractive index of the surface was to be modified to generate the required power variation, simply keeping r fixed in the above equation and computing ni at each position.

[0079] The features as described in the above description, claims and figures can be relevant individually or in any combination to realise the various embodiments of the invention.

Claims

AMENDED CLAIMS received by the International Bureau on 21 November 2025 (21.11.2025)1. An intraocular lens the optical power map of which comprises at least one spiral track and wherein there are at least a first and a second cross section of the spiral track the dioptric range of at least one of which is at least 0.5 dioptre, wherein the average optical power of the first cross section is at least 0.1 dioptre apart from the average optical power of the second cross section, wherein the intraocular lens comprises a spiral zone, wherein the at least one spiral track extends across at least the spiral zone, and wherein at least within the spiral zone the pitch, each measured in the radial direction of the lens, between adjacent spiral track sections increases or decreases as the radius of the spiral track increases.

2. An intraocular lens the optical power map of which comprises a spiral zone, wherein at least one spiral track extends across at least the spiral zone, wherein within the spiral zone there are at least a first and a second cross section of the spiral track the dioptric range of at least one of which is at least 0.5 dioptre, wherein the average optical power of the first cross section is at least 0.1 dioptre but not more than 16 dioptre apart from the average optical power of the second cross section, and wherein the spiral track’s lead within the spiral zone is equal or less than 2000 pm.

3. The intraocular lens of claim 1 or 2, characterised in that it comprises a spiral zone, wherein the at least one spiral track extends across at least the spiral zone, wherein the average optical power of any cross section of the spiral track within the spiral zone is at least 0.5 dioptre, and wherein the first and a second cross section of the spiral track are within the spiral zone.

4. The intraocular lens of any one of claims 1 to 3, characterised in that the average optical power of the first cross section and the average optical power of the second cross section are at least 0.5 dioptre apart.

5. The intraocular lens of any one of claims 1 to 4, characterised in that the dioptric range of the first and the second cross section is at least 0.25 dioptre.

6. The intraocular lens of any one of claims 1 to 5, characterised in that there are no two cross sections of the spiral track the average optical power of which is more than 16 dioptre apart.

7. The intraocular lens of any one of claims 1 to 6, characterised in that the overlap of the dioptric range of a cross section of the spiral track with maximum average optical power and the dioptric range of a cross section of the spiral track with minimum average optical power is less than 2 dioptres.

8. The intraocular lens of any one of claims 1 to 7, characterised in that there is no cross section of the at least one spiral track the dioptric range of which is more than 12 dioptres.

9. The intraocular lens of any one of claims 1 to 8, characterised in that each spiral zone covers an area of at least 0.8 square millimetres.

10. The intraocular lens of any one of claims 1 to 9, characterised in that the spiral zone is ring-shaped.

11. The intraocular lens of any one of claims 1 to10, characterised in that the pitch, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or greater than 10 pm.

12. The intraocular lens of any one of claims 1 to 11 , characterised that the pitch, measured in the radial direction of the lens, between adjacent spiral track sections is equal to or less than 700 pm.

13. The intraocular lens of any one of claims 1 to 12, characterised in that the lead, measured in the radial direction of the lens, is equal to or greater than 10 pm.

14. The intraocular lens of any one of claims 1 to 13, characterised that the lead, measured in the radial direction of the lens, is equal to or less than 2000 pm.

15. The intraocular lens of any one of claims 1 to 14, characterised in that the lead, measured in the radial direction of the lens, is equal to or greater than 10 pm.

16. The intraocular lens of any one of claims 1 to 9, characterised that it comprises two or more parallel spiral tracks.

17. The intraocular lens of any one of claims 1 to 16, characterised in that it comprises six or less parallel spiral tracks.

18. The intraocular lens of any one of claims 1 to 17, characterised in that a non-spiral zone is at the centre of the lens.

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