Prism optical element for presbyopia correction

Abstract

A lens element intended to be worn in front of an eye of a wearer, the lens element comprising:-a holder having at least one first refractive power,-a plurality of sets of optical elements superimposed on the holder, each set of optical elements consisting of a plurality of optical elements, a common focal point Fi of the plurality of optical elements is associated at least with a power Pi, characterized in that, for each group of optical elements, the prism angle of each optical element in this group varies as a function of the distance between the optical element and the common focal point Fi of said group of optical elements.

Description

Technical Field

[0001] The present disclosure relates to lens elements, and in particular to a lens element comprising multiple groups of optical elements. Background Art

[0002] Over the years, the number and complexity of lens designs have continued to increase to meet the diverse needs of individuals. Advances in technology and materials have also contributed to the increase in the number and complexity of lens designs, making it easier to customize and optimize lens designs for individuals.

[0003] Multifocal refractive lenses, such as progressive addition lenses, have been used for many years to correct the wearer's ametropia in a manner suitable for both far and near vision. For this reason, the optical power value of the lens is variable between the far and near vision zones.

[0004] Myopia control lenses that include optical elements that generate signals to control eye elongation have recently received significant attention in the optical field. Typically, the optical elements generate blurred images in front of and / or behind the retina to slow the progression of refractive error.

[0005] This proliferation of lens designs and improvements in the optical properties of lens designs has made the lens manufacturing process more difficult.

[0006] While various solutions for correcting different visual impairments have proven to be of great benefit, they also present attendant disadvantages such as reduced visual comfort for the wearer.

[0007] Finally, the complexity of the lens design makes the lens thicker and less aesthetically pleasing to the wearer.

[0008] The present invention aims to solve the above-mentioned problems of the prior art lens designs. Summary of the Invention

[0009] To this end, the present disclosure proposes a lens element adapted to a wearer and intended to be worn in front of the wearer's eye, for example, comprising:

[0010] - a holder having at least a first refractive power,

[0011] a plurality of optical groups superimposed on a holder, each group consisting of a plurality of optical elements having a common focal point Fi associated with at least one optical power Pi,

[0012] It is characterized in that

[0013] For each set of optical elements, the prism angle of each optical element in this set varies according to the distance between this optical element and the common focus Fi of the optical elements of the set.

[0014] Advantageously, the use of prismatic optics, which can be easily adapted to different lens designs, facilitates the lens manufacturing process. Furthermore, prismatic optics allow for the provision of different optical functions to provide clear vision at different distances while helping to compensate for the wearer's under-accommodation or accommodative lag. Finally, prismatic optics allow for lens elements with reduced thickness and improved aesthetics.

[0015] According to further embodiments which may be considered alone or in combination:

[0016] - the groups of optical elements are arranged in horizontal strips arranged orthogonally to a vertical axis passing through the geometric centre of the lens element; and / or

[0017] - the optical power Pi of the optical element groups is different between two adjacent groups of optical elements; and / or

[0018] - the difference in optical power Pi between two adjacent groups of optical elements is less than or equal to 1.0D, preferably less than or equal to 0.5D, more preferably less than or equal to 0.25D, for example less than or equal to 0.1D; and / or

[0019] - along a vertical axis orthogonal to the zone formed by the groups of optical elements, the average optical power of the optical elements in these groups of optical elements varies; and / or

[0020] - the mean optical power of the optical element increases gradually along the vertical axis and towards the lower part of the lens element; and / or

[0021] - the groups of optical elements are arranged in the lower half of the lens element; and / or

[0022] - the band formed by these groups of optical elements covers the entire width of the lens element; and / or

[0023] - wherein the vertical height of the optical element tape is less than or equal to 5 mm, preferably less than or equal to 4 mm; and / or

[0024] the optical element is a lenslet, the lenslet being shaped so as to be circumscribed by a circle having a diameter less than or equal to 3.0 mm, for example less than or equal to 1.5 mm, for example less than or equal to 1.0 mm, and the diameter of the largest inscribed circle of the lenslet being greater than or equal to 0.1 mm, for example greater than or equal to 0.6 mm; and / or

[0025] - at least a portion, for example all, of the groups of optical elements consist of non-adjacent optical elements; and / or

[0026] - at least a portion of, for example all, the groups of optical elements consist of adjacent optical elements; and / or

[0027] - within a smallest rectangular area encompassing all the optical elements of a group of optical elements, the ratio of the sum of the areas formed by the optical elements to the area of ​​said smallest rectangular area is between 20% and 100%, preferably between 40% and 70%, for example equal to 50%; and / or

[0028] - at least a portion, for example more than 50%, preferably all, of the optical elements are spherical lenslets; and / or

[0029] - at least a portion, for example more than 50%, preferably all, of the optical elements are non-spherical lenslets; and / or

[0030] - at least a portion, for example more than 50%, preferably all, of the optical elements are toric lenslets; and / or

[0031] At least a portion, for example more than 50%, preferably all, of the optical elements are aspherical lenslets. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which:

[0033] - Figure 1 illustrates a schematic outline view of a lens element according to an embodiment of the present disclosure;

[0034] - Figure 2 illustrates a schematic front view of a lens element according to an embodiment of the present disclosure;

[0035] - Figure 3 illustrates a schematic front view of a lens element according to an embodiment of the present disclosure;

[0036] - Figure 4 illustrates a schematic front view of a lens element according to an embodiment of the present disclosure; and

[0037] - Figure 5 Illustrated is a schematic front view of a lens element according to an embodiment of the present disclosure.

[0038] Elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. DETAILED DESCRIPTION

[0039] In the rest of this specification, terms such as "upper", "bottom", "horizontal", "vertical", "above", "below", "front", "back", etc., or other words indicating relative positions may be used. These terms should be understood in the context of wearing the optical lenses.

[0040] The present disclosure relates to a lens element, eg adapted to a wearer and intended to be worn in front of the wearer's eye, eg under standard viewing conditions.

[0041] In the context of the present invention, the term "lens element" may refer to a contact lens, an optical lens, an eyeglass optical lens edged to fit a particular eyeglass frame, an ophthalmic lens, a progressive addition lens, or an optical device adapted to be positioned on an ophthalmic lens. The optical device may be positioned on the front or back surface of the ophthalmic lens. The optical device may be an optical patch or an optical film. The optical device may be adapted to be removably positioned on the ophthalmic lens, such as a clip-on configured to be clipped onto an eyeglass frame including the ophthalmic lens.

[0042] like Figure 1 As shown, lens element 10 includes at least a first surface and a second surface opposite the first surface. For example, the first surface may include object-side surface F1 formed as a convexly curved surface facing the object side, and the second surface may include eye-side surface F2 formed as a concave surface having a curvature different from that of the object-side surface. Alternatively, surfaces F1 and / or F2 may be any of plano, convex, or concave surfaces. Lens element 10 may be made of an organic material (e.g., polycarbonate) or a mineral material such as glass.

[0043] At least a portion, preferably all, of the surface of the lens element 10 may be covered by at least one coating element. The at least one coating element layer may include features selected from the group consisting of anti-scratch, anti-reflection, anti-fouling, anti-dust, UV30 filtering, blue light filtering, and anti-abrasion features.

[0044] The lens element 10 is adapted to the wearer according to a prescription so as to restore the presbyopic eye's ability to see clearly at all distances, but also to optimally respect all physiological visual functions (such as foveal vision, extrafoveal vision, binocular vision) and to minimize undesirable astigmatism.

[0045] The term "prescription" should be understood to refer to a set of optical characteristics, including power, astigmatism, and prismatic deviation, determined by an ophthalmologist or optometrist to correct a visual defect in an eye, for example, with the aid of a lens positioned in front of the wearer's eye. For example, a prescription for myopia includes a power value and an astigmatism value with an axis for distance vision. The prescription may also include an indication that the wearer's eye has no defects and that no optical power will be provided to the wearer.

[0046] In addition to power prescriptions, prescriptions in ophthalmology can include astigmatism prescriptions. This prescription consists of an axis value (measured in degrees) and a module value (measured in diopters). The module value represents the difference between the maximum and minimum power in a given direction, which allows for correction of the wearer's visual default. According to this convention, the axis represents the orientation of one of the two powers relative to a reference axis and following a given rotational direction. The TABO convention can be used. In this convention, the reference axis is horizontal, and the rotational direction is counterclockwise when looking at the wearer. A 45° axis corresponds to an axis that connects the upper right quadrant to the lower left quadrant in an oblique orientation when looking at the wearer. This astigmatism prescription is measured for the wearer under distance vision. The term "astigmatism" is used to refer to the pair (module, axis). The term is sometimes used to specify only the module. A skilled person will readily understand what it refers to based on the context. A skilled person will also appreciate that a wearer's power / astigmatism prescription is typically described using the terms sphere, cylinder, and axis.

[0047] The wearing condition should be understood as the position of the lens element relative to the wearer's eye, as defined by, for example, the anteversion angle, the wrap angle, the cornea-to-lens distance, and ultimately any one of the pupil-to-cornea distance, the eye rotation center (ERC)-to-pupil distance, and the ERC-to-lens distance.

[0048] The cornea-to-lens distance is the distance between the cornea and the back surface of the lens along the visual axis of the eye in the first eye position (usually considered to be horizontal); for example between 6 mm and 20 mm, for example between 8 mm and 16 mm, preferably between 10 mm and 14 mm, more preferably equal to 12 mm.

[0049] The pupil-to-corneal distance is the distance between the pupil and the cornea of ​​the eye along its visual axis; it is usually between 1 mm and 4 mm, for example equal to 2 mm.

[0050] The ERC-to-pupillary distance is the distance along the visual axis of the eye between its center of rotation (ERC) and the cornea; for example between 10 mm and 15 mm, preferably between 11 mm and 12 mm, more preferably equal to 11.5 mm.

[0051] The ERC to lens Q'O distance is the distance between the ERC of the eye and the back surface of the lens along the visual axis of the eye in the first eye position (usually considered to be horizontal), for example between 20 mm and 30 mm, preferably between 22.5 mm and 28 mm, more preferably equal to 25.5 mm.

[0052] The anteversion angle is the angle in the vertical plane between the normal to the back surface of the lens and the visual axis of the eye in the first ocular position (usually considered to be horizontal) at the intersection between the back surface of the lens and the visual axis of the eye in the first ocular position; for example between -25° and +5°, preferably between -12° and 0°, more preferably between -10° and -6°, for example equal to -8° or 0°.

[0053] The wrap angle is the angle in the horizontal plane between the normal to the back surface of the lens and the visual axis of the eye in the first ocular position (usually considered to be horizontal) at the intersection between the back surface of the lens and the visual axis of the eye in the first ocular position, for example between -10° and +25°, preferably between 0° and 10°, more preferably between 0° and +5°, for example equal to 0°.

[0054] An example of a standard wearing condition may be defined by an anteversion angle of -8°, a cornea-to-lens distance of 12 mm, a pupil-to-cornea distance of 2 mm, an ERC-to-pupil distance of 11.5 mm, an ERC-to-lens distance of 25.5 mm, and a wrap angle of 0°.

[0055] Another example of a standard wearing condition that is more suitable for younger wearers may be defined by an anteversion angle of 0°, a cornea-to-lens distance of 12 mm, a pupil-to-cornea distance of 2 mm, an ERC-to-pupil distance of 11.5 mm, an ERC-to-lens distance of 25.5 mm, and a wrap angle of 0°.

[0056] like Figures 1 to 5 As illustrated, the lens element 10 comprises a holder 12 having at least a first refractive power P.

[0057] According to an embodiment of the present disclosure, the first refractive power P is based on a prescription suitable for correcting the wearer's far vision. For example, the first refractive power P may be suitable for focusing an image of an object located at a distance greater than 2 meters from the lens element on the wearer's eye. In other words, when the wearer wears the lens element under standard wearing conditions and looks directly at an object located at infinity, light from the object, passing through the holder and the eye, will form a sharp image on the retina of the eye.

[0058] The holder 12 may have a refractive power P that varies continuously between a first refractive power P and a second refractive power P. Preferably, the variation of the refractive power of the holder is monotonic.

[0059] like Figures 1 to 5 As illustrated, lens element 10 includes multiple groups of optical elements 14 .

[0060] In the sense of the present disclosure, the expression "group of optical elements" is to be understood as a group of optical elements that share a common feature, such as a common focus. Thus, the corresponding areas projected onto the lens element and comprising all optical elements of two different groups of optical elements may overlap.

[0061] These sets of optical elements 14 are superimposed on the holder 12 of the lens element 10. In the sense of the present disclosure, the expression "superimposed" is understood as being located on the front surface F1 of the lens element and / or on the back surface F2 of the lens element and / or between the front and back surfaces of the lens element.

[0062] Each of these groups of optical elements is formed from a plurality of optical elements, for example, more than three optical elements, preferably more than five optical elements, and more preferably more than ten optical elements. The common focal point Fi of the optical elements in a group is associated with at least one first optical power Pi. In other words, light originating from a point object and passing through any optical element in the group and through the holder on which the optical element is superimposed will be focused at a single focal point Fi. Within the meaning of the present invention, the term "common focal point" is understood to mean a volume located within a 3D sphere, the geometric center of which corresponds to the mean focal point of the optical elements and has a radius between 0.01 mm and 0.5 mm.

[0063] The prism angle value and orientation of each optical element in a set of optical elements vary depending on the distance between that optical element and the common focal point Fi of the set of optical elements. In other words, the prism of each optical element in a set of optical elements depends on the relative position of that optical element to the common focal point of the set of optical elements. For example, two optical elements in a set of optical elements that are equidistant from the common focal point of the set of optical elements may have similar prism values ​​but different prism orientations.

[0064] Advantageously, variations in the prism angles and orientation of the optical elements allow for compensation for variations caused by the peripheral shape of the lens and / or the shape of the wearer's eye by deflecting light toward a common focal point.

[0065] All optical elements in a set of optical elements can have the same refractive power. Alternatively, some of the optical elements in a set can have a different refractive power than the other optical elements. In this case, the prism values ​​and orientations of these optical elements are defined to compensate for the different refractive powers so that the focal points of the optical elements are aligned with the common focal point Fi of the set.

[0066] The optical elements in a set of optical elements can all have a common size and / or a common shape. Alternatively, the size and / or shape of each optical element in a set of optical elements can be different. In this case, the prism values ​​and orientations of the optical elements are defined to compensate for the different sizes and / or shapes so that the focal points of the optical elements are aligned with the common focal point Fi of the set.

[0067] The optical powers Pi of adjacent groups of optical elements differ from each other. Within the meaning of the present disclosure, two groups of optical elements are considered to be adjacent if a section through the geometrical centre of a lens element continuously passes through the minimum projected area encompassing all optical elements in each group of optical elements.

[0068] The difference in optical power Pi between two adjacent groups of optical elements may be less than or equal to 1.0 D, preferably less than or equal to 0.5 D, more preferably less than or equal to 0.25 D, for example less than or equal to 0.1 D. Advantageously, having a smaller optical power difference between adjacent groups of optical elements improves the visual comfort of the wearer.

[0069] Different groups of optical elements can be spatially separated from each other. Alternatively, different groups of optical elements can partially or completely overlap. For example, two different groups of lens elements can be evenly spread to cover a portion of the lens element.

[0070] It will be understood that the optical function of an optical element results from the combination of the optical power Pi of the optical element and the refractive power of the holder on which the optical element is superimposed, both being considered under standard wearing conditions.

[0071] like Figure 2 As illustrated, the sets of optical elements 14 may be arranged over the entire surface of the lens element 10 .

[0072] For example, the lens element 10 may include two different groups of optical elements 14, namely, a first group of optical elements 24a and a second group of optical elements 24b. The first group of optical elements 24a may be disposed in the upper portion of the lens element and may have an optical function suitable for providing the wearer with clear vision for distance vision. The optical power P1 of the optical elements 24a is defined such that when the wearer wears the lens element under standard wearing conditions and views an object at infinity through the first group of optical elements, the common focal point F1 of the object image coincides with the retina. The second group of optical elements 24b may be disposed in the lower portion of the lens element and may have an optical function suitable for providing the wearer with clear vision for near vision. The optical power P2 of the optical elements 24b is defined such that when the wearer wears the lens element under standard wearing conditions and views an object at reading distance through the second group of optical elements, the common focal point F2 of the object image coincides with the retina.

[0073] like Figure 3 As shown, the sets of optical elements 14 can be arranged to partially cover a portion of the surface of the lens element 10. For example, the sets of optical elements can be arranged in the lower half of the lens element. Alternatively, the optical elements can be arranged in the upper region and / or the nasal region and / or the temporal region of the lens element.

[0074] For example, a lens element includes two different groups of optical elements 14: a first group of optical elements 34a and a second group of optical elements 34b. The holder 12 may have a first refractive power P suitable for focusing light from objects at a distance (e.g., greater than two meters) onto the wearer's retina when the lens element is worn under standard wearing conditions. The first group of optical elements 34a may be arranged into two different subsets: a first subset, with the lens elements in the first subset positioned in close contact and grouped together in the lower half of the lens element, and a second subset, with the lens elements in the second subset dispersed near the group of optical elements in the first subset. The lens elements in the first group of optical elements may have an optical function suitable for providing the wearer with clear vision for near vision. The optical power of the optical elements 34a is defined such that when the wearer wears the lens element under standard wearing conditions and views an object at reading distance through the first group of optical elements, the common focal point F1 of the object's image coincides with the retina. The second group of optical elements 34b may be disposed in the lower portion of the lens element and may have an optical function suitable for providing myopia control to slow the progression of refractive error in the eye. The second group of optical elements 34b may have an optical function suitable for focusing light from an object located at infinity beyond the wearer's retina when the wearer is looking straight ahead. In other words, when the lens element is worn under standard wearing conditions, the common focal point F2 of the second group of optical elements 34b is located in front of or behind the wearer's retina.

[0075] exist Figure 3 In an alternative embodiment to the illustrated embodiment, the first refractive power P of the holder may no longer be limited to distance vision. At least a portion (e.g., the entirety) of the portion of the holder not covered by the first and second optical groups is covered by a third optical group. The third optical group, together with the holder overlaid with the optical elements, provides an optical function suitable for focusing light from an object at a distant distance (e.g., at infinity) onto the wearer's retina.

[0076] like Figure 4 As shown, multiple groups of optical elements 14 can be arranged in bands, such as parallel bands and / or horizontal bands. The horizontal bands of optical elements can be arranged orthogonally to a vertical axis passing through the geometric center of the holder. For the purposes of this disclosure, the term "horizontal band" should be understood as the smallest rectangular area encompassing all optical elements in a group. The terms "horizontal" and "vertical" should be understood in the context of standard wearing conditions. For example, all optical elements in a group can be aligned to form a single horizontal row of optical elements within the horizontal band.

[0077] Preferably, the horizontal strips formed by different groups of optical elements do not overlap. Alternatively, the horizontal strips formed by different groups of optical elements may partially overlap. For example, the surfaces of the horizontal strips of optical elements from two groups may overlap by less than 50%, preferably less than 25%, and more preferably less than 10%.

[0078] The horizontal strips formed by the optical elements of the different groups preferably cover the entire width of the lens element. In the sense of the present disclosure, it is understood that the horizontal width of the smallest rectangular area surrounding all the optical elements of a group covers at least 75%, preferably more than 80%, more preferably 90% of the horizontal width of the lens element passing through said rectangular area.

[0079] The vertical height of the horizontal strips of optical element packages is less than or equal to 10 mm, preferably less than or equal to 7.5 mm, more preferably less than or equal to 5 mm, for example less than or equal to 4 mm.

[0080] The average optical power of the optical elements in different groups of optical elements may vary from group to group along a vertical axis orthogonal to the horizontal band. For example, the average optical power of the optical elements may increase along the vertical axis toward the lower portion of the lens element. Alternatively, the average optical power of the optical elements may decrease along the vertical axis toward the lower portion of the lens element. For example, the average optical power of the optical elements forming each group of optical elements may increase toward the lower portion of the lens element and then further decrease.

[0081] The increase and / or decrease in the average optical power of the optical elements from one group of optical elements to an adjacent group of optical elements may be monotonous and / or gradual. For example, the average optical power of the optical elements may increase regularly by 0.25D from one group of optical elements to a successive group of optical elements.

[0082] Similar to the average power of an optical element, the equivalent spherical value of the optical elements in these groups of optical elements can vary from group to group. The equivalent spherical value of an optical element is a well-known parameter of the optical element, which corresponds to the average spherical value of the optical element plus half its cylindrical value.

[0083] according to Figure 4 In the illustrated embodiment of the present invention, lens element 10 includes five different groups of optical elements arranged in horizontal strips. The optical elements in the first group 44a may have an average optical power of 1.0D. The optical elements in the second group 44b may have an average optical power of 1.25D. The optical elements in the third group 44c may have an average optical power of 1.5D. The optical elements in the fourth group 44d may have an average optical power of 1.75D. The optical elements in the fifth group 44e may have an average optical power of 2.0D. In this example, the average optical power gradually and continuously increases from 1.0D toward the lower periphery of the lens element.

[0084] The jump in average power between successive groups of optical elements may be greater than 0.25 D, for example greater than or equal to 0.5 D, to increase the progression of power along the vertical axis. Additionally or alternatively, the number of groups of optical elements may be increased to obtain a stronger progression of power along the vertical axis.

[0085] Advantageously, such an arrangement of different groups of optical elements allows providing a lens element with a progressive addition lens design, the optical power of which gradually transitions from a first optical power to a second optical power.

[0086] like Figure 5 As illustrated, the sets of optical elements 14 may be arranged as concentric rings on the surface of the lens element 10. For example, the sets of optical elements may be arranged as a plurality of rings centered about the geometric center (eg, optical center) of the lens element.

[0087] For example, the lens element 10 may include five different groups of optical elements 14. The holder 12 may have a first refractive power P adapted to a prescription for correcting ametropia (e.g., myopia or hyperopia) in the wearer's eye. The respective optical powers of the optical elements 54a, 54b, 54c, 54d, and 54e are defined such that when the wearer wears the lens element under standard wearing conditions and looks directly at an object at infinity, light passing through the optical elements will be focused in front of and / or behind the wearer's retina. In other words, when the lens element is worn under standard wearing conditions, the focal points Fi associated with the optical powers Pi of the groups of optical elements are defined to be positioned in front of and / or behind the wearer's retina.

[0088] Advantageously, focusing these sets of optical elements on another location other than the wearer's retina generates a refractive error control signal, such as a myopia control signal that slows the progression of refractive error in the eye.

[0089] Preferably, the optical powers Pi of the different groups of optical elements increase with radial distance from the geometrical centre and / or the optical centre of the lens elements.

[0090] Alternatively, the holder 12 may have a refractive power P and further include another set of optical elements 14 that, together with the holder on which the set of optical elements is superimposed, provide an optical power suitable for correcting the refractive error of the wearer's eye. In this example, the additional set of optical elements is arranged in a plurality of concentric rings that alternate with the other sets of optical elements.

[0091] At least a portion, for example, more than 50%, and preferably all of the optical elements 14 in these groups of optical elements may be lenslets, and the outline shape of these lenslets is a circle with a circumscribed diameter greater than or equal to 0.1 mm, for example, greater than or equal to 0.4 mm, preferably greater than or equal to 0.6 mm, and more preferably greater than or equal to 0.8 mm, and can be inscribed in a circle with a diameter less than or equal to 3.0 mm, preferably less than or equal to 1.5 mm, for example, less than or equal to 1.0 mm.

[0092] The ratio of the sum of the areas of the optical elements 14 of the different groups of optical elements to the area of ​​the surface of the holder on which they are superimposed is between 20% and 100%, preferably between 30% and 80%, for example between 40% and 60%.

[0093] Within a minimum rectangular area surrounding all optical elements in a group of optical elements, the ratio of the sum of the areas formed by the optical elements to the area of ​​the minimum rectangular area is between 20% and 100%, preferably between 40% and 70%, for example equal to 50%.

[0094] like Figure 2 、 Figure 4 and Figure 5 As indicated, at least a portion, for example more than 50%, and preferably all, of the optical elements 14 in these groups of optical elements may be contiguous.

[0095] like Figure 3 As indicated, at least a portion, for example more than 50%, and preferably all, of the optical elements 14 in at least one group of optical elements may be non-contiguous.

[0096] In the sense of the present disclosure, two optical elements are contiguous if there is a path supported by a surface of a lens element connecting two optical elements located on said surface of the lens element and if, along said path, the base surface of the lens element on which the optical element is superimposed is inaccessible.

[0097] When the surface on which at least two optical elements are superimposed is a spherical surface, the base surface corresponds to the spherical surface. In other words, if there is a path connected to the two optical elements superimposed on the spherical surface, supported by the spherical surface, and if the spherical surface cannot be reached along the path, then the two optical elements are contiguous.

[0098] When a surface on which at least two optical elements are superimposed is non-spherical, the base surface corresponds to the local spherical surface that best fits the non-spherical surface. In other words, if there is a path that is supported by the non-spherical surface and connects two optical elements superimposed on the non-spherical surface, and if the spherical surface that best fits the non-spherical surface cannot be reached along the path, then the two optical elements are contiguous.

[0099] At least one, for example more than 50%, preferably all, of the optical elements in at least one group of optical elements may be spherical lenslets.

[0100] At least one, for example, more than 50%, and preferably all, of the optical elements in at least one group of optical elements may be non-spherical lenslets. Within the meaning of the present disclosure, the term "non-spherical" is understood to mean not having a single focus. Unlike spherical lenslets, which have a constant refractive power across their surface, non-spherical lenslets do not have the same curvature and refractive power across their surface.

[0101] Preferably, the non-spherical lenslet is a non-spherical refractive lenslet. Therefore, not having a single focal point means that the non-spherical refractive lenslet has more than one focal point. In this case, the common focal point Fi of the optical elements in a group of optical elements should be read as the average focal point.

[0102] At least one, for example more than 50%, preferably all of the optical elements 14 may include cylindrical power.At least one, for example more than 50%, preferably all of the optical elements 14 may be toric lenslets.

[0103] According to embodiments of the present disclosure, the optical elements comprising these groups of optical elements include cylindrical powers. The cylindrical power of each optical element can depend on its distance from the geometric center of the lens element. For example, the cylindrical value of an optical element can increase or decrease depending on the radial distance from the geometric center of the lens element. The cylindrical power of each optical element can also depend on its position on the lens element. For example, the cylindrical value of an optical element can increase or decrease depending on its coordinates in the TABO convention.

[0104] Advantageously, varying the cylindrical power of an optical element as a function of its position on the lens element allows compensating for the astigmatism caused by the shape of the lens element and therefore allows reducing the spatial dispersion of the common focus of these groups of optical elements.

[0105] At least one, for example more than 50%, preferably all of the optical elements may be a multifocal refractive lenslet. In the sense of the present disclosure, "multifocal refractive lenslet" includes bifocal lenses (having two focal powers), trifocals (having three focal powers), and progressive multifocal lenses (having continuously varying focal powers, such as lenses with aspheric surfaces).

[0106] At least one, for example more than 50%, preferably all, of the optical elements 14 in at least one group of optical elements may be aspherical lenslets. In the sense of the present invention, an aspherical lenslet has a continuous power progression on its surface, for example from the geometrical or optical center of the lenslet to its periphery, and the absolute value of the refractive power at its periphery is smaller or higher than the absolute value of the refractive power at its center.

[0107] The absolute value of the difference between the refractive power measured at the center of an aspheric lenslet and the refractive power measured at its periphery can be between 0.1D and 5D. The lenslet center can be defined by a circular area centered at the geometric center of the lenslet and having a diameter between 0.1mm and 0.5mm, preferably equal to 0.2mm. The lenslet periphery can be defined by an annular area centered at the geometric center of the lenslet and having an inner diameter between 0.5mm and 0.7mm and an outer diameter between 0.70mm and 0.80mm. For example, an aspheric lenslet can have a refractive power measured at its geometric center with an absolute value between 2.0D and 7.0D, and an optical power measured at its periphery with an absolute value between 1.5D and 6.0D.

[0108] At least one, for example more than 50%, preferably all, of the optical elements 14 may comprise an aspherical surface with or without rotational symmetry.

[0109] At least one, for example, more than 50%, and preferably all, of the optical elements 14 may include a toric surface. A toric surface is a surface of revolution that can be produced by rotating a circle or arc about an axis of revolution that does not pass through its center of curvature (ultimately located at infinity). A toric surface lens has two different radial profiles at right angles to each other, thereby producing two different focal powers. The toric and spherical surface components of a toric lens produce an astigmatic beam rather than a single point focus.

[0110] The lens element may further include a plurality of optical elements that are not part of the sets of optical elements. For example, the plurality of optical elements may have optical powers adapted to produce an amount of focused or defocused light in front of and / or behind the wearer's retina to generate a refractive error control signal that reduces the progression of refractive error in the eye.

[0111] As will be apparent from the following discussion, unless specifically stated otherwise, it should be understood that throughout this specification, discussions utilizing terms such as "operate," "compute," "generate," etc., refer to the actions and / or processes of a computer or computing system or similar electronic computing device that manipulate and / or transform data represented as physical (e.g., electronic) quantities within the computing system's registers and / or memories into other data similarly represented as physical quantities within the computing system's memories, registers, or other such information storage, transmission, or display devices.

[0112] Embodiments of the present invention may include an apparatus for performing the operations described herein. The apparatus may be specially constructed for the desired purpose, or the apparatus may include a general-purpose computer or a digital signal processor ("DSP") selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer-readable storage medium, such as, but not limited to, any type of disk, including a floppy disk, an optical disk, a CD-ROM, a magneto-optical disk, a read-only memory (ROM), a random access memory (RAM), an electronically programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic card or an optical card, or any other type of medium suitable for storing electronic instructions and capable of being coupled to a computer system bus.

[0113] The process and display presented herein are not inherently related to any specific computer or other equipment. Various general-purpose systems can be used together with the program according to the teachings herein, or it can prove very convenient to build more specialized equipment to perform the desired method. The desired structure of various such systems will appear from the following description. In addition, embodiments of the present invention are not described with reference to any specific programming language. It should be appreciated that various programming languages ​​can be used to implement the teachings of the present invention described herein.

[0114] Numerous further modifications and variations will be apparent to those skilled in the art upon reference to the foregoing illustrative embodiments, which are presented by way of example only and are not intended to limit the scope of the disclosure, which is to be determined solely by the appended claims.

[0115] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the disclosure.

Claims

1. A lens element intended to be worn in front of a wearer's eye, the lens element comprising: - a holder having at least a first refractive power, a plurality of groups of optical elements superimposed on the holder, each group consisting of a plurality of optical elements having a common focal point Fi associated with at least one optical power Pi, It is characterized by: For each set of optical elements, the prism angle of each optical element of this set varies according to the distance between said optical element and the common focus Fi of the optical elements of the set.

2. A lens element according to claim 1, wherein The sets of optical elements are arranged in horizontal strips arranged orthogonally to a vertical axis passing through the geometric center of the lens element.

3. A lens element according to any one of claims 1 to 2, wherein The optical power Pi of the optical element groups between two adjacent optical element groups is different.

4. A lens element according to claim 3, wherein The difference in optical power Pi between two adjacent groups of optical elements is less than or equal to 1.0D, preferably less than or equal to 0.5D, more preferably less than or equal to 0.25D, for example less than or equal to 0.1D.

5. A lens element according to any one of claims 2 to 4, wherein Along a vertical axis orthogonal to the zone formed by the plurality of groups of optical elements, the average optical power of the optical elements in the groups of optical elements varies.

6. A lens element according to claim 5, wherein The mean optical power of the optical element gradually increases along the vertical axis and towards a lower portion of the lens element.

7. A lens element according to any one of the preceding claims, wherein The set of optical elements is arranged in the lower half of the lens element.

8. A lens element according to any one of claims 2 to 7, wherein The strip formed by the set of optical elements covers the entire width of the lens element.

9. A lens element according to any one of claims 2 to 8, wherein The vertical height of the optical element strips is less than or equal to 5 mm, preferably less than or equal to 4 mm.

10. A lens element according to any one of the preceding claims, wherein The optical element is a small lens, and the shape of the small lens is circumscribed by a circle with a diameter less than or equal to 3.0 mm, for example, less than or equal to 1.5 mm, for example, less than or equal to 1.0 mm, and the diameter of the largest inscribed circle is greater than or equal to 0.1 mm, for example, greater than or equal to 0.6 mm.

11. A lens element according to any one of the preceding claims, wherein At least a portion of the set of optical elements consists of non-adjacent optical elements.

12. A lens element according to any one of the preceding claims, wherein At least a portion of the set of optical elements consists of adjoining optical elements.

13. A lens element according to any one of claims 1 to 12, wherein Within a minimum rectangular area surrounding all optical elements in a group of optical elements, the ratio of the sum of the areas formed by the optical elements to the area of ​​the minimum rectangular area is between 20% and 100%, preferably between 40% and 70%, for example equal to 50%.

14. A lens element according to any one of claims 1 to 13, wherein At least a portion, for example more than 50%, preferably all, of the optical elements are spherical lenslets.

15. A lens element according to any one of claims 1 to 13, wherein At least a portion, for example more than 50%, preferably all, of the optical elements are aspherical lenslets.

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