WO2024253528A1

WO2024253528A1 - Combinations of variable optics for accommodating intraocular lens

Info

Publication number: WO2024253528A1
Application number: PCT/NL2024/050296
Authority: WO
Inventors: Michiel Christiaan Rombach
Original assignee: Akkolens International BV
Current assignee: Akkolens International BV
Priority date: 2023-06-06
Filing date: 2024-06-06
Publication date: 2024-12-12
Anticipated expiration: 2025-12-06

Abstract

Accommodating intraocular lens construction with two optical elements fitted each with sets free-form optical surfaces. A combination of such sets include a first set of surfaces comprising free-form optical surfaces to, in combination, provide desired variable defocus power and a second set with surfaces to provide variable spherical power to provide variable extended depth of field for vision at near while preserving contrast sensitivity for vision at far and a third set with surfaces to provide desired variable piston power for additional defocus and, in selected cases, sets with surfaces to provide variable correction of undesired astigmatism and coma. The optical powers of all sets all depend on the degree of mutual shift of the optical elements in a direction perpendicular to the optical axis.

Description

COMBINATIONS OF VARIABLE OPTICS FOR ACCOMMODATING INTRAOCULAR LENS

The present invention discloses optical designs for free-form optical surfaces for accommodating lenses including at least two optical elements fitted with optical surfaces with the elements fitted with haptics, anchors, to position the lens in the eye and to transfer movement of driving means in the eye to shift the optical elements in a direction perpendicular to the optical axis. Such accommodating lenses have been disclosed in numerous documents, for example W02005084587, WO2011053143, EP1932492B1 and US2005324673 and various other documents mentioned therein.

The optical designs disclosed in the present document concern novel combinations of polynomials for free-form optical surfaces (meaning: rotationally asymmetrical optical surfaces, generally of a ‘saddle shape’, but not restricted thereto in addition to earlier prior art disclosures in particular disclosed US20153422728 and US2016076714, which disclose only lenses with variable defocus.

The present discloses combinations of sets of variable power lenses to increase, or, alternatively, decrease aberrations with the combinations fitted onto two optical elements of an accommodating lens construction. A first set of surfaces comprises free-form optical surfaces provides desired variable defocus optical power, a second set provides desired a variable spherical power for variable extension of depth of field specifically for vision at near, a third set provides desired variable piston power for additional variable defocus and, in selected cases, a fourth set provides correction of undesired variable astigmatism and a fifth set can, in selected cases, provide correction of undesired variable astigmatism. A set of such surfaces includes at least two, largely similar, complementary surfaces with at least one such surface fitted onto each optical element.

Multiple, generally two, complementary and free-form optical surfaces are mounted on separate optical elements, with the elements arranged along an optical axis, and provide a lens of variable aberration with the order of aberration depending on the shape of the free-form surfaces and the degree of optical power depending on the degree of mutual displacement optical elements, for example mutual shift, rotation or wedge. In this present document the terms/abbreviations for variable defocus, or spherical, or piston, or astigmatism, or coma lens mean ‘a variable lens comprising at least two free-form optical surfaces with the lens providing a variable degree of optical power with the degree of the optical power depending on the degree of mutual displacement of at least one of the free-form surfaces in a direction perpendicular to the optical axis’. The defocus optical power (generally, but not restricted to, positive optical power for defocus) is provided by two 3^rd order freeform optical surfaces (also: cubic surfaces), as originally disclosed in US3350294, and, variable (primary) spherical optical power (generally, but not restricted to, negative optical power for extension of depth of field) by two 5^th order free-form surfaces, and, variable piston optical power (generally, but not restricted to, positive optical power for additional defocus power) by two 1^st free-form order surfaces. Note that additional free-form optical surfaces can also provide for, positive or negative, a variable coma, a variable astigmatism, variable trefoils, and so forth along the Zernike orders, all of orders can be included by expanding the terms in the mathematical framework set forth in this document.

Note that, within the sets, the free-form surfaces are generally not precisely equal. Free-form surfaces on the posterior optical element may require minor optical corrections to correct for focusing of the fixed optical power of the cornea and any fixed optical power lens fitted to the anterior optical element.

Sets of complementary surfaces relevant to the present document include, but are not restricted to, for desired defocus and extended depth of field: combinations at least two surfaces according to a 3^rd order polynomial (for variable defocus power) and at least two complementary surfaces according to a 5^th order polynomial (for variable spherical power) and at least two complementary surfaces according to a 1^st order polynomial (for variable piston power). For correction of undesired aberrations at least two surfaces according to a 4^th order polynomial (for correction of variable coma) and/or at least two surfaces according to a 3^rd order polynomial (for correction of variable astigmatism) can be included in the combination.

Table 1 : The ’ANSI Standard Zernike Mode Pyramid’ terminology followed in this document:

Variable lenses will be referred to as ‘variable piston lens’ providing variable piston, ‘variable defocus lens’ providing variable defocus, ‘variable spherical lens’ providing variable sphere, ‘variable coma’ lens providing variable coma and ‘variable astigmatic lens ’ for vertical, or horizontal, or oblique variable astigmatism.

The optical design of such accommodating intraocular lens can be described in the form of grouped polynomial terms with the polynomial terms in brackets creating variable or fixed aberrations, as in, for example:

where z is the surface sag along the optical axis, A represents the cubic coefficient for the amplitude defocus, B specifies the degree of correction of variable astigmatism (due to shift of at least one fixed power lens which can be part of the lens construction), D is the coefficient reducing the thickness of the lens, C is the coefficient for the correction of variable coma during movement in the lateral direction, P represents the static spherical aberration term with P

0 only for the posterior free-form surface.

Alternatively, a series of extended polynomials offers an alternative mathematical notation which combines multiple terms into a single, free-form, surface:

wherein A_{p q} are the coefficients. The grouped polynomial terms in the lens surface expression above can all be expressed using such extended polynomials. In such notation the free-form surfaces can be modified to add variable sphere with the amplitude depending on the lateral shift dx of the optical element. In particular, the following terms X5Y0, X3Y2 and X1 Y4 are added to create a variable, shiftdependent, fourth-order term (x² + y²)² in addition to the 3^rd order defocus term X3Y2. Note that ‘spherical power’, in the context of the present document, relates only to 4^th order variable (primary) spherical rotationally symmetrical power (see Table 1 ).

The defocus power of the lens construction, albeit at loss of contrast sensitivity, is increased by integration of 5^th order terms into the sag-equation which integration generates variable sphere. In particular, the following X/Y terms, in transversal coordinates, X5Y0, X3Y2 and X1 Y4 are added to create a variable sphere. To create such integration the ‘Extended Polynomial’ section of the ‘Zemax® OpticStudio’ optical simulation software can be applied (which manual can be considered to be included in the present document: https://support.zemax.com/hc/en-us/articles/1500005575422-How-to-model-a- black-box-optical-system-using-Zernike-coefficients) for S2 and S3 (as in Fig. 1) can be, without the variable 4^th order parameter sets of 5^th order: X1 Y0, X2Y0, X3Y0, X1 Y2, X4Y0, X2Y2, X0Y4 to which the variable sphere 4^th order term by the parameter set X5Y0, which can which term can be further optimized by reiterated digital modifications of added terms such as X3Y2 and X1 Y4 with which modifications not restricted to only these terms.

Note that the parameters X/Y for the S2 surface and S3 must differ to reach the complementary optical effect because for the S3 optical surface the optical effects of the S2 optical surface must be taken into account as well as the focusing effect of the first optical element and effects of different distance of the S3 surface from any optical component anterior of the lens construction, for example the cornea of the eye. Prior art documents: EP1932492B1/US12518458 discloses multiple order surfaces for simultaneous variable correction of one or more undesired variable optical aberrations of the natural eye and/or the accommodating intraocular lens. Neither mention nor hint is made to variably increase a desired aberration, for example, to provide a variable extension of depth of field. As in Claim 1 , dependent Claims and in the text: ‘accommodating intraocular lens with variable optical power, comprising at least two optical elements, at least one of which is movable relative to the other in a direction perpendicular to the optical axis wherein the optical elements have such a form as to result in a lens with different optical power at different relative positions of the optical elements, characterized in that at least two of the optical elements of the lens comprises at least one additional optical correction surface which correction surfaces are adapted for simultaneous variable correction of one or more optical aberrations of the natural eye’ and, discloses, in Claims (1 -4 and 7): ‘Accommodating intraocular lens with variable optical power, comprising at least two optical elements [...] wherein the optical elements have such a form as to result in a lens with different optical power at different relative positions of the optical elements, characterized in that at least two of the optical elements of the lens comprises at least one additional optical correction surface which correction surfaces are adapted for simultaneous variable correction of one or more optical aberrations of the natural eye in which the degree of correction depends on the relative position of the optical elements’ [...] ‘the lens is adapted for variable focusing and for variable correction of variable higher-order aberrations of the remaining optical surfaces of the human eye’ [...] which ‘occur during the accommodation process of the eye’ [...] which ‘correction surfaces simultaneously correct aberrations of more than one order to correct variable defocus and variable spherical aberration simultaneously. US2015342728 I WO2013055212 and WO2016076714(A1 ), NL20142013761 disclose additional free-form surfaces in addition to the 3^rd order cubic, defocus, surfaces to variably correct, meaning: decrease, correct for, undesirable variable astigmatism and variable coma which, undesirable, aberrations are generated by other optical surfaces of the lens and which can occur in parallel with variable sphere. No mention is made of adding such additional surfaces to variably increase any aberration other than variable defocus aberration to provide variable extended depth of field in addition to variable defocus. US3583790 and US4650292 disclose 5^th order surfaces for variable correction of undesired variable sphere but do not mention such additional surfaces to variably increase any desired aberration. The document does not mention any additional surfaces to variably increase any aberration to provide variable extended depth of field. WO2011053143 (also US2012323321 ) discloses, in Claims: ‘Lens according to any of the foregoing claims, characterized in that the lens comprises a combination of a lens for variable focus [variable spherical aberration] comprising a telescope arrangement and a lens for variable focus’, and ‘Lens characterized in that the lens comprises at least one additional surface for fixed correction of fixed aberrations other than fixed focus’ and, in text, discloses: ‘So, the lens comprises at least one additional surface for variable correction of variable aberrations other than variable focus to provide variable correction of at least one variable aberration [...] such embodiment will require at least two additional surfaces for variable correction of variable aberrations’. No mention or hint is made of any additional surfaces to variably increase any aberration to extent depth of field.

W02009051477 discloses only variable defocus by: ‘positioning in the eye and adjustment of an accommodating intraocular artificial lens, a lens with variable optical power, comprising two optical elements which [...] mutually move (by shift, rotation or combination thereof), in a direction perpendicular to the optical axis wherein the optical elements have such a shape that they exhibit, in combination, different optical powers at different relative positions’. No mention or hint is made of any additional surfaces added to the variable defocus to variably decrease or increase any desired and/or any undesired aberration.

Prior art document US2008215146 discloses ‘an intra-ocular artificial lens with variable optical strength (meaning: as in text: variable-defocus), comprising at least two optical elements [...] wherein at least one of the movable optical elements is connected to positioning means which are adapted for coupling to the iris of the eye for the purpose of driving’. No mention or hint is made of any additional surfaces added to the variable defocus to variably decrease or increase any aberration other than variable defocus. US2009062912 discloses mechanical constructions of a lens with variable optical power comprising two optical elements with no mention or hint made of any additional surfaces added to the variable defocus. W020050845871 US2008046076 discloses: ‘Application of artificial intra ocular lens according to one of the preceding claims, characterized by application of the lens for correction of a disorder of the eye’. W02020027652 / NL2019050443 discloses: ‘a lens with two optical elements each with a free-form optical surface [...] one of the elements also comprises a wave front encoding phase mask, for example, a modified cubic mask, a mask with a gradually increasing cubic term’ and, in the Claims 1 -3: ’Variable focus lens [...] comprising at least two optical elements [...] each fitted with at least one free-form optical surface [...] with one element also comprises at least one wave front encoding phase mask [...] to provide extended depth of field, EDOF and ‘the lens comprises a mask which mask is adapted to provide a fixed degree of EDOF which degree is independent of the degree of defocus of the lens’ or ‘the lens comprises a mask which mask is adapted to provide a variable degree of EDOF which degree is dependent on the degree of defocus’. This document discloses a wave-front encoding phase mask, a single free-form surface, to achieve extended depth of field in combination with a variable defocus lens similar as set forth under the ‘first set of free-form optical surfaces’ in the present document. The present invention discloses a variable spherical lens comprising two free-form surfaces as set forth under the ‘second set of free-form optical surfaces’. Note that an asymmetrical combination of two 3^rd order optical surfaces, two cubic surfaces, with one of the surfaces for example being steeper compared to the other surface can provide such single wave-front encoding phase mask by increasing the 3^rd order optical distortion which distortion provides extended depth of field. Document NL-2032859, Accommodating intraocular lens comprising a combination of multiple variable lenses, discloses an accommodating intraocular lens with a combination of variable lenses. The combination includes a variable lens with two fixed optical power lenses fitted onto two optical elements to provide variable defocus of which the degree of power depends on the degree of movement of at least one of fixed power lens along the optical axis and a variable lens with at least two cubic surfaces fitted onto the same two optical elements which provides a lens of variable optical power of which the degree depends on the degree of movement of at least one of the optical elements in a direction perpendicular to the optical axis. Such combination clearly differs from the combination set forth in the present document, of three variable lenses each comprising free-form surfaces and each changing optical power by movement of optical elements perpendicular to the optical axis. shows the optical element with the S indications referring to the optical surfaces, at the resting state with minimal contributions of the variable defocus lens and spherical lenses, with the optical axis, 1 , the anterior optical element, 2, the posterior optical element, 3, a weak fixed power lens mounted on the anterior side of the anterior optical element, 4, a strong fixed power lens mounted on the posterior side of the posterior optical element, with both these fixed power lenses providing correction of the refraction of the aphakic eye (an eye lacking a refractive lens) and with free form optical surfaces mounted on the posterior side of the anterior element and the anterior side of the posterior element, 6.

Fig. 2 illustrates the same elements in the accommodated state under mutual displacement of the optical elements, in this example a shift of the elements over the distances 8, 9. (refer also to Fig. 10-11 for an illustration of a, prior art, preferred embodiment of an accommodating lens construction). show the simulated modulus of the Optical Transfer Function (OTF Fig.

3) and the simulated through-focus modulation transfer function (MTF, Fig. 4) of a design of a accommodated, in this example focused at 30cm distance, meaning a lens with shifted elements, of a lens construction with optical surfaces according to the terms X1 Y0, X2Y0, X3Y0, X1 Y2, X4Y0, X2Y2, X0Y4, according to only the first set optical surfaces providing the variable defocus lens, in Fig. 3, the theoretical diffraction limited response, 10, and the simulated lens responses, 11 (also at off- axis fields). Fig. 4 shows the simulated MTF of such lens with the central focal peak, 12, representing the MTF at the focal spot with the focal peak flanked by undulating tails, 13, 14, a negative, myopic tail, and a positive, hyperopic, tail which tails and undulations are due to contributions of, multiple, non-defocus optical aberrations.

Note that the non-defocus optical aberrations in the positive direction, the hyperope direction, contribute to a, non-functional, extended depth of field, meaning the aberrations mainly result in undesired loss of contrast sensitivity by vision at far and that the non-defocus optical aberrations in the negative direction, the myope direction, contribute to a, desired and functional, extended depth of field, albeit at the cost of some loss of contrast sensitivity at near.

Note: In case the first set the free-form surfaces are mutually aligned, for vision at far, the of variable sphere has a minimal contribution. The diffraction-limited of such MTF = - irccos

MTF is given by: ⁿ , where is the spatial frequency expressed in cycles/mm,

= 397 _Cy_C|_es/_mm j_s the _cut- off spatial frequency. So, we have

a cycles/mm. The simulated through-focus MTF plot depicted above reveals that the image quality on the retina (at 50 cycles/mm) remains high at the full dis-accommodation of the lens construction and the depth of focus remains relatively narrow. show the simulated modulus of the Optical Transfer Function (OTF) and the simulated modulation transfer function (MTF) of a design of a lens construction with optical surfaces according to the terms X1 Y0, X2Y0, X3Y0, X1 Y2, X4Y0, X2Y2, X0Y4 to which a variable sphere is added by the terms X5Y0, X3Y3 and X1Y4. The sets of optical surfaces providing a variable sphere with, in Fig. 5, the OTF with the theoretical diffraction limited response, 15, and the simulated lens responses, 16, at slightly off-axis fields. Fig. 6 illustrates the MTF of the simulated performance of such lens focused at near, meaning: the lens accommodated, in this example, at 30cm, with the central focal peak, 17, representing the MTF at the focal spot with the focal peak flanked by tails, 18, 19. The negative, tail, 18, is pronounced compared to the negative tail, 14, in Fig. 4, resulting in an increased extended depth of field at near vision while the positive tail, 19, is virtually absent, compared to the positive tail, 13, in Fig. 4, resulting in limited and undesired extended depth of field at far vision preserving contrast sensitivity. So, this lens construction comprises a first set of optical surfaces for variable defocus and a second set optical surfaces for variable sphere with the spherical addition limited to only vision at near.

Fig.7 shows that, by adapting the parameters of the terms in the design formulas the negative tail, 20a, can be adjusted providing an even further increased depth of field albeit at the cost of further reduced visual acuity, a reduced central focal peak, 20, from 0,8 to 0,7. So, the optical performance of the lens construction can be fine-tuned according to the requirements of individual eyes. Fig. 8 shows a combination of Fig. 4 and Fig. 6 for illustration purposes. In conclusion, addition of variable sphere (1) reduces the central focal peak, 21 , (2) increases extended depth of field at near vision, 21 a, and (3) does bot affect extended depth of field at far vision, 22, 23, preserving contrast sensitivity.

The through-focus modulation transfer function (MTF) plot reveals that the image quality on the retina (in this example at 50 cycles/mm) remains high at the full dis- accommodation of the lens for vision at far. However, it is important to note that the depth of focus remains relatively narrow at full dis-accommodation preserving high contrast sensitivity. It is also clear that the MTF amplitude decreases but remains at a high level >0.65. Note: It is important to highlight that the plots displayed illustrate the through-focus Modulation Transfer Functions (MTFs) at a spatial frequency of 50lp/mm, with near vision focal peaks aligned at the zero through-focus position. The lens exhibits an anterior shift in the absolute position of the near focal peak providing an additional variable sphere which results in an accommodative power of -+0.5 D. Steeper cubic surfaces can be programmed by adjusting the parameters of the polynomial term X3Y2 to further enhance the variable defocus power. The extended depth of field can be increased by a higher (in absolute terms) negative variable sphere power which can be provided by adjusting the parameters of the polynomial terms X5Y0. When the IOL is focused at far distances, the through-focus response MTF plots (at 50 Ip/mm, pupil size = 3 mm, X=546 nm) show no significant changes in the MTF peak.

9-10 show for illustration purposes, with the light traveling from top to bottom, the optical surfaces of the lens with the weak anterior fixed optical power lens, 24, the posterior free-form surface, 25, of the anterior optical element, the posterior strong fixed power optical lens of the posterior element, 26, and the anterior freeform surface, 27, of the posterior element. show for illustration purposes a preferred embodiment of the lens construction with in Fig. 11 , a top view, the, overlapping, optical elements, 24, the connection component between the optics and the haptics, 25, the elastic hinge, 26, to reposition the optics to a resting state at relaxation of the ciliary muscle, or, alternatively, a MEMS and a flange, 27, to anchor the haptics into the sulcus of the eye. Fig. 12 shows, a side view, the optical elements, 28, 29, the flange, 30, and the barrel of the lens construction, 31 , coupled to driving means, generally the ciliary muscle of the eye, or, alternatively, in advanced embodiments, a MEMS with the direction of shift of the optical elements, 32, at contraction and relaxation of driving means which can be natural, or, alternatively, artificial driving means.

Human vision requires a visual acuity of >0.8 for sharp distance vision while the visual acuity can drop to 0.4-0.5 for vision at near, for example, an acuity required for reading. An accommodating intraocular lens providing variable ‘asymmetric extended depth of field’, by a variable sphere, at near in addition to variable defocus can be designed by methods disclosed in the present document. Note that multiple free-form surfaces according to multiple free-form shapes can be, in practice, combined into a single free-form shape per optical element, fitted to one side of the element, or, alternatively, combined into two free-form shape per optical element with one of such shapes on each side of the element. The degrees of optical power of the variable defocus and variable sphere lenses can be adjusted to fit the requirements of the particular eye into which the lens is implanted. For example, the distribution of contrast sensitivity over full range of vision can be finetuned by the adapting the parameters X5Y0, X3Y2 and X1 Y4 of the mathematical notation z = S(x,y) = _lp,qA_Piqx^py^q to customize lenses for a particular eyes and according to desired outcomes for the wearer of the intraocular lens.

The present document discloses accommodating intraocular lens constructions comprising at least two optical elements with each of the elements fitted with at least one free-form optical surfaces and with the optical elements fitted with haptics to transfer movement of driving means in the eye to the optical elements with the free-form optical surfaces including (1 ) a first set of free-form optical surfaces which set is composed of two 3^rd order complementary surfaces with one complementary surface on each optical element with the set providing a lens of variable defocus power (for variable defocus) with the degree of power depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye and (2) a second set of free-form optical surfaces which set is composed of two 5^th order complementary surfaces with one complementary surface on each optical element with the set providing a lens of variable spherical power (for variable sphere) with the degree of power depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye and (3) a third set of free-form optical surfaces which set is composed of two 1 ^st order complementary surfaces with one complementary surface on each optical element with the set providing a lens of variable piston power (for variable piston/defocus) with the degree of power depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye, and, optional, in case the intraocular lens construction also comprises a fixed power lens to correct for the refractive error of the aphakic eye, a (4) a fourth set of free-form optical surfaces which set is composed of two 4^th order complementary surfaces with one complementary surface on each optical element with the set providing a lens of, positive or negative, variable astigmatism power (for variable astigmatism) with the degree of power depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye. Lastly, an additional set can be added, a set of free-form optical surfaces which set is composed of two 4^th order complementary surfaces with one complementary surface on each optical element with the set providing a lens of, positive or negative, variable coma power (for variable coma) with the degree of power depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye. Note that, within all sets, the free-forms optical surfaces are largely identical but not precisely identical because of the focusing effect of the cornea and the anterior optical element for which effect the free-form surfaces on the posterior element must be corrected.

The variable defocus provided by the first set of free-form optical surfaces can be a positive or a negative defocus with the positive defocus the preferred defocus of which the degree of optical power increasing with an increasing degree of mutual shift of the optical elements (meaning: increased shift provides a lens of increased positive optical power), and, the variable sphere power provided by the second set of free-form optical surfaces can be a positive or a negative sphere with the negative sphere the preferred sphere of which the degree of optical power decreases with an increasing degree of mutual shift of the optical elements (meaning: increased shift provides a lens of increased negative optical power), and, the variable piston provided by the third set of free-form optical surfaces can be a positive or a negative piston with the positive piston the preferred power of which the degree of positive optical power increases with an increasing degree of mutual shift of the optical elements (meaning: increased shift provides a lens of increased positive optical power), and, the variable coma aberration provided by the additional sets of free-form optical surfaces such as, but not restricted to, variable positive or a negative coma and variable astigmatism of which the degree of optical power changes with an increasing degree of mutual shift of the optical elements. Multiple free-form surfaces can be combined in a single free-form surface according to, for example, a formula for a series of extended polynomials as in: z =

All the degrees of variable optical power of the variable defocus, variable sphere and variable piston can be adjusted to fit requirements of the particular eye into which the lens is implanted. The lens construction can comprise a combination of at least one fixed optical power refractive lens and at least three sets of free-form optical surfaces, or, alternatively, the lens construction can comprise only at least three sets of free-form optical surfaces which lens construction can be implanted in the eye in combination with an, independent, fixed optical power refractive lens, for example, the lens construction implanted in the sulcus of the eye with a fixed optical power refractive lens, a monofocal or multifocal lens, implanted in the capsular bag of the eye, providing a phakic eye (an eye with a refractive lens), or, alternatively, a lens construction comprising at least three sets of free-form optical surfaces which lens construction can be implanted in the eye in combination with the natural lens (a natural phakic eye). Any number of free-forms surfaces can, per optical element, be combined in a single free-form surface.

The driving means in the eye can be at least one natural component of the eye, for example, the ciliary mass of the eye and/or the capsular bag of the eye, or, alternatively, the driving means in the eye can be an artificial driving means implanted in the eye, for example a MEMS (Micro-Electro-Mechanical System) device.

So, in summary, this document discloses accommodating intraocular lens constructions comprising at least two optical elements with the optical elements and fitted with haptics to transfer movement of driving means in the eye to the optical elements wherein each element is fitted with a combination of at least two free-form sets optical surfaces with the degree of variable power of the sets depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye with the sets of free-form surfaces including a first set of free-form optical surfaces which set comprises at least two 3^rd order complementary surfaces with one complementary surface on each optical element with the set providing lens for variable defocus (a 2^nd order aberration), a second set of free-form optical surfaces which set comprises at least two 5^th order complementary surfaces with one complementary surface on each optical element with the set providing a lens for variable sphere (a 4^th order aberration), a third set of free-form optical surfaces which set at least two 1 ^st order complementary surfaces with one complementary surface on each optical element with the set providing a lens for variable piston (the 0^th order aberration), furthermore the combination can also include a set of free-form optical surfaces which set comprises at least two 3^rd order complementary surfaces with one complementary surface on each optical element with the set providing a lens for variable astigmatism (a 2^nd order aberration), and, the combination can also include a set of free-form optical surfaces which set comprises at least two 4^th order complementary surfaces with one complementary surface on each optical element with the set providing a lens for variable coma (a 3^rd order aberration), and, lastly, the combination of free-form optical surfaces can also include additional any set, or, alternatively, additional sets, of at least two free-form surfaces to provide variable powers of any order, and, per optical element, any number of free-forms surfaces can be combined by at least one series of extended polynomials into a single freeform surface, or, alternatively, per optical element, any number of free-forms surfaces can combined in two independent free-form surfaces to, for example, surfaces fitted onto both sides of a single optical element with, for all embodiments, the variable defocus provided by the first set of free-form optical surfaces can be a positive variable defocus, and, the variable sphere can be a negative variable sphere, and, the variable piston can be a positive piston, and, any additional variable optical power can be a variable positive or a negative, and the lens construction can, but not necessarily has to, comprise a combination of at least one fixed optical power refractive lens and at least two sets of free-form optical surfaces, or, alternatively, the lens construction can comprise sets of free-form optical surfaces which lens construction is implanted in the eye in combination with an, independent, fixed optical power refractive lens which can be a fixed power monofocal lens, or, alternatively, a fixed power(s) multifocal focal lens, or, alternatively, such lens construction can be implanted in the eye in combination with the natural lens of the eye with the lens construction driven by any natural driving means, for example, the ciliary muscle of the eye, or, alternatively, driven by artificial driving means, for example, at least one MEMS (Micro Electro-Mechanical System).

The invention thus relates to an accommodating intraocular lens construction comprising at least two optical elements with the optical elements and fitted with haptics to transfer movement of driving means in the eye to the optical elements wherein each element is fitted with a combination of at least three free-form sets optical surfaces with the degree of variable optical power of the sets depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye with the sets of free-form surfaces including a first set of free-form optical surfaces which set comprising at least two 3^rd order complementary surfaces with one complementary surface on each optical element with the set adapted to provide lens of variable defocus power, and, a second set of free-form optical surfaces which set comprising at least two 5^th order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable spherical power, and, a third set of free-form optical surfaces which set comprising at least two 1^st order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable piston power. The combination of free-form optical surfaces can also include a set comprising at least two 3^rd order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable astigmatism power and/or the combination of free-form optical surfaces can also includes a set comprising at least two 4^th order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable coma power. The combination of free-form optical surfaces can also include at least one set comprising at least two free-form optical surfaces with the set to providing variable power of any other order.

In the lens construction, per optical element, the free-form surfaces may thus be combined in a single free-form surface by extended polynomial series with the single free-form surface fitted to a single side of the optical element.

Per optical element, the free-form surfaces can be combined in two free-form surfaces by extended polynomial series with the free-form surfaces fitted onto both sides of the optical element. The lens construction can comprise a combination of at least one fixed optical power refractive lens and at least two sets of free-form optical surfaces with the lens construction preferably suitable to be implanted in an aphakic eye. The lens construction can comprises a combination of at least two sets of free-form optical surfaces with the lens construction preferably suitable to be implanted in a phakic eye. The lens construction can be adapted to be driven by natural driving means, or, alternatively, the lens construction can be adapted to be driven by artificial driving means.

Claims

1 . Accommodating intraocular lens construction comprising at least two optical elements with the optical elements and fitted with haptics to transfer movement of driving means in the eye to the optical elements wherein each element is fitted with a combination of at least three free-form sets optical surfaces with the degree of variable optical power of the sets depending on the degree of mutual shift of the elements in a direction perpendicular to the optical axis of the eye with the sets of free-form surfaces including:

- a first set of free-form optical surfaces which set comprising at least two 3rd order complementary surfaces with one complementary surface on each optical element with the set adapted to provide lens of variable defocus power,

- a second set of free-form optical surfaces which set comprising at least two 5th order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable spherical power,

- a third set of free-form optical surfaces which set comprising at least two 1 st order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable piston power.

2. Lens construction according to Claim 1 wherein the combination of free-form optical surfaces also includes a set comprising at least two 3rd order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable astigmatism power.

3. Lens construction according to Claim 1 wherein the combination of free-form optical surfaces also includes a set comprising at least two 4th order complementary surfaces with one complementary surface on each optical element with the set adapted to provide a lens of variable coma power.

4. Lens construction according to any Claim 1-3 wherein the combination of free-form optical surfaces also includes at least one set comprising at least two free-form optical surfaces with the set to providing variable power of any other order.

5. Lens construction according to any Claim 1-4 wherein, per optical element, the free-form surfaces are combined in a single free-form surface by extended polynomial series with the single free-form surface fitted to a single side of the optical element.

6. Lens construction according to any Claim 1-4 wherein, per optical element, the free-form surfaces are combined in two free-form surfaces by extended polynomial series with the free-form surfaces fitted onto both sides of the optical element.

7. Lens construction according to any Claim 1-5 wherein the lens construction comprises a combination of at least one fixed optical power refractive lens and at least two sets of free-form optical surfaces with the lens construction to be implanted in an aphakic eye.

8. Lens construction according to any Claim 1-7 wherein the lens construction comprises a combination of at least two sets of free-form optical surfaces with the lens construction to be implanted in a phakic eye.

9. Lens construction according to any Claim 1-7 wherein the lens construction is adapted to be driven by natural driving means.

10. Lens construction according to Claims 1 -7 wherein the lens construction is adapted to be driven by artificial driving means.