Mandrels used in processing ophthalmic lenses

Abstract

A mandrel (1) for holding an ophthalmic lens member blank (52) during processing is disclosed. The mandrel (1) includes a front face (6) for receiving the ophthalmic lens member blank (52) to be processed, a rear face (8) opposite the front face, and one or more through holes (10) extending between the front face and the rear face (6, 8). In use, wax applied to the rear face (8) contacts the ophthalmic lens member blank (52) received on the front face (6) through the one or more through holes (10). Also disclosed is a method of manufacturing an ophthalmic lens using such a mandrel, and a lens manufactured using such a mandrel.

Description

[Technical Field]

[0001] The present disclosure relates to mandrels used in the fabrication of ophthalmic lenses, particularly (but not limited to) contact lenses. The present disclosure relates to mandrels for holding ophthalmic lens element blanks during fabrication, kits of parts including such mandrels, methods for mounting ophthalmic lens element blanks on mandrels, methods for fabricating ophthalmic lens element blanks, and ophthalmic lenses fabricated using such mandrels and / or methods. [Background technology]

[0002] Ophthalmic lenses are often manufactured by machining an ophthalmic lens blank, for example, to provide a desired shape and surface finish. Such operations require a high degree of precision to ensure the finished lens has the required properties. Mandrels are used to hold the ophthalmic lens blank during machining, for example, to mount the lens blank on a lathe for cutting, or to hold the lens blank during polishing or grinding.

[0003] Typically, a block of wax is provided in front of the mandrel, and the lens blank is pressed into the wax. The wax then holds the lens blank in place. Obtaining accurate placement of the lens blank on the wax and a consistent wax thickness can be difficult. This can cause the lens blank to misalign or tilt relative to the mandrel, resulting in processing errors. The wax can also leave residue on the lens surface, causing the surface to appear hazy or cloudy, which can affect the optical performance of the lens. The wax residue must then be cleaned. If the cleaning is not successful, or if the cleaning scratches the lens (as often occurs), the lens will not achieve the required optical performance (either due to scratches or wax residue). It would be advantageous to provide a method for holding ophthalmic lens blanks during processing to reduce processing errors, provide lenses with improved optical performance, and / or provide a reduced error rate for the lenses produced.

[0004] Recently, ophthalmic lens assemblies have been proposed in which optical components are housed within the lens. Examples of optical components include diffractive optical elements and electrically switchable components such as liquid crystal cells. Such assemblies can be manufactured by encapsulating the optical components between first and second lens elements. The first and second lens elements may define the anterior and posterior surfaces of the lens therebetween, or the first and second lens elements may define an encapsulating component that is then encapsulated within a lens material to form the anterior and / or posterior surfaces of the lens. It would be advantageous to provide an efficient method for machining such lens assemblies. Such assemblies may require more precise machining to achieve the required dimensions given the number of components involved (e.g., considering tolerance stackup) and / or may require a higher level of machining accuracy to allow the optical components to provide the required effect. Therefore, more precise processing techniques can be particularly advantageous when applied to such ophthalmic lens assemblies.

[0005] As an alternative to using wax, a mandrel may be provided with a recess that closely matches the dimensions of the lens blank, allowing the lens to be held on the mandrel by an interference fit between the recess and the blank. However, a tight fit between the lens blank and the recess may result in excessive force on the blank during machining, potentially resulting in a distorted lens after cutting. Furthermore, this technique may be limited in terms of the blank shapes that can be used. For example, it is difficult to machine blanks with very thin edges using this method, as it is difficult to position the thin edges on the sides of the recess. It would be advantageous to provide a method for holding ophthalmic lens blanks during machining that reduces error rates, provides lenses with improved optical performance, and / or allows a wider range of lens blank shapes to be machined.

[0006] The present disclosure aims to alleviate the aforementioned problems. Alternatively or additionally, the present disclosure aims to provide improved apparatus and / or methods for use in fabricating ophthalmic lenses. Summary of the Invention

[0007] In a first aspect, the present disclosure provides a mandrel for holding an ophthalmic lens element blank during processing, the mandrel comprising: a front surface for receiving an ophthalmic lens element blank to be processed; a rear surface opposite the front surface; and one or more through holes extending between the front and rear surfaces, wherein, in use, wax applied to the rear surface contacts the ophthalmic lens element blank received on the front surface through the one or more through holes.

[0008] In a second aspect, the present disclosure provides a parts kit comprising a mandrel according to the first aspect, the mandrel having a socket in its front face for receiving an adapter, the parts kit including one or more of the following: an adapter having a convex end configured to be received in the socket such that the convex end defines a portion of the front face of the mandrel; an adapter having a concave end configured to be received in the socket such that the concave end defines a portion of the front face of the mandrel; an adapter having a flat end configured to be received in the socket such that the flat end defines a portion of the front face of the mandrel.

[0009] In a third aspect, the present disclosure provides a method of mounting an ophthalmic lens element blank on a mandrel, the mandrel having a front surface, a rear surface, and one or more through holes extending between the front and rear surfaces, the method comprising: holding the ophthalmic lens element blank against the front surface of the mandrel; and while the ophthalmic lens element blank is held against the front surface of the mandrel, applying wax to the rear surface of the mandrel, wherein the wax flows through the one or more through holes and contacts the rear surface of the ophthalmic lens element blank at the through holes.

[0010] In a fourth aspect, the present disclosure provides a method of processing an ophthalmic lens element blank, comprising the steps of: mounting the ophthalmic lens element blank on a mandrel according to the method of the third aspect; releasing the holding so that the lens element blank is held on the mandrel by the wax; and processing a front surface of the ophthalmic lens element blank while the lens element blank is held on the mandrel.

[0011] In a fifth aspect, the present disclosure provides a batch of 1000 ophthalmic lenses, each lens processed using the mandrel of the first aspect and / or the second aspect and / or manufactured using the method of the third aspect and / or the fourth aspect, each lens comprising a central optical zone and an annular peripheral zone surrounding the central optical zone, the central optical zone of each lens being free of wax residue and scratches, and at least one of the lenses having an annular peripheral zone including a surface with wax residue and / or scratches.

[0012] In a sixth aspect, the present disclosure provides an ophthalmic lens processed using the mandrel of the first aspect and / or the second aspect and / or manufactured using the method of the third aspect and / or the fourth aspect, the lens comprising a central optical zone and a peripheral zone surrounding the central optical zone, the central optical zone being free of wax residue and scratches, and the peripheral zone comprising a surface having wax residue and / or scratches.

[0013] Optional but preferred features are set out in the dependent claims.

[0014] Of course, it will be understood that features described in connection with one aspect of the present disclosure may be incorporated in other aspects of the present disclosure, for example, a method of the present disclosure may incorporate any of the features described with reference to an apparatus of the present disclosure, and vice versa.

[0015] Exemplary embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which: [Brief explanation of the drawings]

[0016] [Figure 1A] FIG. 1A shows a cross-sectional view of a mandrel according to one embodiment of the present disclosure.

[0017] [Figure 1B] FIG. 1B shows a front view of the mandrel of FIG. 1A.

[0018] [Figure 1C] FIG. 1C shows a cross-sectional view of the mandrel of FIG. 1A with an ophthalmic lens blank assembly attached.

[0019] [Figure 2A] FIG. 2A shows a perspective view of a mandrel according to one embodiment of the present disclosure.

[0020] [Figure 2B]FIG. 2B shows a front view of the mandrel of FIG. 2A.

[0021] [Figure 2C] FIG. 2C shows a cross-sectional view of the mandrel of FIG. 2A.

[0022] [Figure 3A] FIG. 3A shows a perspective view of a mandrel according to one embodiment of the present disclosure.

[0023] [Figure 3B] FIG. 3B shows a front view of the mandrel of FIG. 3A.

[0024] [Figure 3C] FIG. 3C shows a cross-sectional view of the mandrel of FIG. 3A.

[0025] [Figure 4] FIG. 4 shows a schematic cross-sectional view of a mandrel according to one embodiment of the present disclosure, with an ophthalmic lens element blank attached to the mandrel and the mandrel mounted on a lathe for machining the lens element blank.

[0026] [Figure 5] FIG. 5 illustrates a flow chart of a method for mounting an ophthalmic lens element blank on a mandrel in accordance with the present disclosure.

[0027] [Figure 6] FIG. 6 illustrates a support assembly used in mounting a lens element blank onto a mandrel according to one embodiment of the present disclosure.

[0028] [Figure 7] FIG. 7 shows a photograph of an ophthalmic lens element manufactured using a mandrel, according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] According to a first aspect of the present disclosure, there is provided a mandrel for holding an ophthalmic lens element blank during processing (machining). The mandrel may include a front surface for receiving an ophthalmic lens element blank to be processed (machined), a rear surface opposite the front surface, and / or one or more through holes extending between the front and rear surfaces. The mandrel may be configured such that, in use, wax applied to the rear surface contacts the ophthalmic lens element blank attached to the front surface through the one or more through holes.

[0030] Use of such a mandrel may allow wax to be applied to the ophthalmic lens element blank at one or more discrete locations defined by the through-holes. The lens element blank, positioned against the anterior surface, may contact (and then be held by) the wax at the opening of the through-hole in the anterior surface of the mandrel. This may improve precision when the lens element blank is positioned on the mandrel, eliminating variability introduced by the need to apply a wax layer with a consistent thickness and / or to press the lens element blank to a consistent depth into the wax layer, thereby reducing processing errors. Additionally or alternatively, controlling and limiting the area in which the wax contacts the lens element blank may reduce the impact of wax residue on the optical performance of the lens.

[0031] The term machining may refer to cutting, grinding, polishing, and / or other machining processes. Examples of machine tools to which the present disclosure may be applied may include lathes, grinders, polishers, and / or other machine tools.

[0032] The anterior surface of the mandrel may have an optic zone and a peripheral zone, and the one or more through-holes may be located within the peripheral zone. Locating the through-holes within the peripheral zone may improve the optical performance of the lens by positioning wax residue outside the optic zone. The optic zone of the anterior surface may be located at the center of the anterior surface. The mandrel may be configured such that the optic zone of the anterior surface is aligned with the optic zone of the lens element blank when the lens element blank is received on the anterior surface. The peripheral zone of the anterior surface may be radially outside the optic zone, e.g., the peripheral zone may be annular and surround the optic zone. The mandrel may be configured such that the peripheral zone of the anterior surface is aligned with the peripheral zone of the lens element blank when the lens element blank is received on the anterior surface. The through-holes of the mandrel may be limited to the peripheral zone. A through-hole extending between the anterior and posterior surfaces may be located within the peripheral zone. The anterior surface of the mandrel may be convex, concave, or flat within the optic zone.

[0033] The anterior surface of the mandrel, e.g., the optic zone, may have a concave, bowl-shaped surface region configured to receive the convex surface of the lens element blank. The anterior surface of the mandrel, e.g., the optic zone, may have a convex, dome-shaped surface region configured to receive the concave surface of the lens element blank. The bowl-shaped region or dome-shaped region may be surrounded by a planar surface region. The anterior surface of the peripheral zone may have a substantially planar surface. Thus, the shape of the anterior surface may match the shape of the anterior or posterior surface of the lens element blank.

[0034] The mandrel may have a stem for mounting the mandrel on a machine tool. The stem may have an elongated body configured to be received in a chuck of the machine tool. The mandrel may have a flange extending radially from the stem, for example, at one end of the stem. The flange may have a front surface, a rear surface (e.g., the surface of the flange opposite the front surface), and / or one or more through holes. The diameter of the stem may be less than 50% of the diameter of the flange. The front and / or rear surfaces may be substantially perpendicular to the stem (regardless of any recesses formed therein). The longitudinal axis of the through hole may be substantially parallel to the longitudinal axis of the stem and / or the rotational axis of the mandrel when mounted on the machine tool.

[0035] The mandrel may include a plurality of through holes. The plurality of through holes may be spaced about a longitudinal axis of the mandrel and / or stem. The through holes may be equally spaced about the longitudinal axis.

[0036] The front surface of the mandrel may have a front recess shaped to receive an ophthalmic lens element blank. The front recess may be configured to receive the lens element blank by a location fit, rather than an interference fit, for example. A "location fit" may be defined as a fit in which the dimensions of the recess match the blank, such that the blank is substantially immobile within the recess in the radial direction, but will fall out of the recess when the mandrel is inverted in the absence of wax to hold the blank in place. This contrasts with an interference fit, in which the blank is retained within the recess even when the mandrel is inverted in the absence of wax. The dimensions of the front recess may closely match the dimensions of the ophthalmic lens element blank. Providing a front recess shaped to closely match the shape of the lens element blank may improve the accuracy and reliability of positioning the lens element blank on the mandrel (thereby reducing processing errors). The front recess may have a diameter of 4 mm to 20 mm, for example, 10 mm to 20 mm. The mandrel's optic zone can be substantially circular and have a diameter of 2 mm or more and 10 mm or less. In some embodiments, the anterior recess can have a diameter of 13 mm to 15 mm, and the mandrel's optic zone can have a diameter of 7 mm to 9 mm. The depth of the anterior recess can be 1 mm or less, for example, the depth of the outer edge of the anterior recess can be 0.8 mm to 0.2 mm. The depth of the anterior recess can be less than the thickness of the lens element blank at the outer edge of the anterior recess. The depth of the anterior recess can vary with radius, for example, if the anterior surface includes a convex or concave region within the optic zone. Providing a shallower recess can allow a mandrel with a wider range of lens thicknesses to be used while still machining the entire surface of the lens blank. Depth can be measured relative to the outer edge of the mandrel's anterior face, such as the outer edge of the anterior flange face. If the longitudinal position of the outer edge of the mandrel's anterior face varies around the circumference, the average position of the anterior face edge should be used when measuring the recess depth. The front recess may be defined by a raised region, for example an annular raised region, which may be centered on the mandrel and disposed, for example, on the front surface.The raised region can be concentric with the anterior recess, the optic zone, and / or the peripheral zone.

[0037] The rear surface of the mandrel may have a rear recess, e.g., an annular recess. The rear recess may be centered on the rear surface and / or concentric with the rear surface. The rear recess may be centered on the flange and / or concentric with the longitudinal axis of the flange and / or mandrel. The depth of the rear recess may be greater than the depth of the front recess. The depth of the rear recess may be 5 mm or less, e.g., 0.5 mm to 0.4 mm. The depth may be measured relative to the position of the outermost edge of the rear surface, e.g., the outer edge of the rear surface of the flange. If the longitudinal position of the outer edge of the rear surface varies around the circumference, the average position of the rear surface edge should be used when measuring the depth of the recess. Multiple through-holes, e.g., each or all of the through-holes, may be in fluid communication with the rear recess and / or with each other through the rear recess. Thus, wax dispensed into the rear recess may be able to flow into the multiple through-holes. By providing a rear recess through which wax can be provided to multiple through-holes, a user may simply dispense (pour) wax into the rear recess (rather than dispensing (pour) wax into each hole individually), which may help to provide a more uniform distribution of wax, thereby improving the reliability of the retention provided by the mandrel during use and / or improving ease / efficiency of use (e.g., by reducing the number of wax dispensing steps).

[0038] Each through-hole may have a first opening on the front surface and a second opening on the rear surface. The first opening may be located within the front recess and / or the second opening may be located within the rear recess. The through-hole may extend between the first and second openings. Thus, the first and second openings may define ends of the through-hole. The first opening may be located at the bottom of the front recess. The second opening may be located at the bottom of the rear recess. The through-holes have a longitudinal axis. When viewed in a cross section perpendicular to their longitudinal axis, the through-holes may be substantially circular, kidney-shaped, and / or arc-shaped, for example, arc-shaped with a constant radius relative to the center of the front surface. The periphery of the first and second openings (i.e., the edges of each opening) may be curved and may not include discontinuities (unsmooth portions), such as sharp corners.

[0039] The front surface of the mandrel may have one or more drainage channels through which wax and / or air can flow from the front recess. By providing drainage channels, excess wax may be drained from the area of ​​the through-holes, reducing variations in the amount of wax protruding beyond the through-hole openings in the front surface (which may affect the position of the lens element blank on the front surface and increase the risk of machining errors). Additionally or alternatively, providing drainage channels may reduce the risk of air bubbles forming between the blank and the mandrel. The drainage channels may extend from the edges of the front recess. The drainage channels may extend from the edges of the through-holes, e.g., the through-hole openings. Drainage channels extending directly from the through-holes in the front surface may be particularly advantageous in that they reduce the accumulation of excess wax.

[0040] The front surface may have a raised region defining a front recess. The front surface may further have a reservoir, for example, located radially outward of the raised region. The reservoir may be connected to the front recess by one or more of the drainage channels, allowing excess wax in the front recess to flow to the reservoir via the drainage channels. The front surface of the raised region may be substantially planar (regardless of the presence of the drainage channels). Providing a reservoir on the front surface may be a simple mechanical method for collecting excess wax and thereby preventing it from contacting the lens element blank in areas other than its intended location. The reservoir may be deeper than the front recess. The drainage channels may extend radially in a straight line from the front recess to the reservoir. This arrangement may facilitate the flow of wax from the front recess to the reservoir. The reservoir may take the form of an annular channel defining the periphery of the raised region.

[0041] In some embodiments, the anterior recess is substantially circular, the raised region is substantially annular, and the reservoir is substantially annular. The anterior recess, raised region, and reservoir may be concentric, and may be in the following order from inside to outside: anterior recess, raised region, reservoir.

[0042] A second aspect of the present disclosure provides a kit of parts including a mandrel having any of the features described above in connection with the first aspect. The mandrel may further include a socket in its front surface for receiving an adapter. The kit of parts may further include one or more of the following: an adapter having a convex (dome-shaped) end configured to be received in the socket such that the convex end defines a portion of the front surface of the mandrel; an adapter having a concave (bowl-shaped) end configured to be received in the socket such that the concave end defines a portion of the front surface of the mandrel; or an adapter having a flat end configured to be received in the socket such that the flat end defines a portion of the front surface of the mandrel. In this manner, an adapter may be used to provide a convex or concave region on the front surface, as described above in the first aspect. Such a reconfigurable mandrel / kit may provide improved manufacturing efficiency and / or ease of manufacture.

[0043] In a third aspect of the present disclosure, there is provided a method for mounting an ophthalmic lens element blank, such as a contact lens element blank, on a mandrel for machining (i.e., as part of a machining process). The mandrel may have a front surface, a rear surface, and one or more through holes extending between the front and rear surfaces. The method may include holding the ophthalmic lens element blank against the front surface of the mandrel, for example, holding the posterior surface of the ophthalmic lens element blank against the front surface of the mandrel. The method may include applying wax to the posterior surface of the mandrel while the ophthalmic lens element blank is held against the front surface of the mandrel. The method may include flowing wax through the one or more through holes to contact the posterior surface of the ophthalmic lens element blank at the through holes while the ophthalmic lens element blank is held against the front surface of the mandrel.

[0044] The method may include contacting the wax only with the posterior surface of the ophthalmic lens element blank at the through hole. The method may include allowing the wax to harden. The method may include releasing the hold on the lens element blank (e.g., after the wax has hardened) and the blank is held by the wax.

[0045] The method may include placing an ophthalmic lens element blank on a support, for example, a support having a bowl-shaped recess or a dome-shaped protrusion on its upper surface that matches (mimics) the front surface of the blank. The method may include, for example, placing a mandrel over the lens element blank on the support, such that the weight of the mandrel itself holds the lens element blank against the front surface of the mandrel. The method may include, for example, dispensing wax onto the rear surface of the mandrel while the mandrel is resting on the lens element blank and while the rear surface of the mandrel is uppermost. The method may include holding, and optionally depressing, the mandrel before and / or during the wax dispensing step. It will be apparent that the force required to hold the blank against the mandrel will depend in part on the pressure, flow rate, and amount (volume) of wax dispensed. When the wax is dispensed slowly at low pressure in a volume substantially equal to the volume of the through-hole, the wax does not push the blank away from the front surface, and therefore little or substantially no force is required to hold the blank in place. When higher flow rates, pressures, and volumes are involved, it may be necessary to hold the blank against the surface with some force. The method may include using a fixture having, for example, a cavity configured to receive a portion of the stem, to hold the mandrel in place while the wax is being dispensed. The use of a support and fixture may help maintain alignment of the mandrel and lens element while the wax is being applied, thereby reducing the risk of machining errors.

[0046] In a fourth aspect of the present disclosure, there is provided a method for machining an ophthalmic lens element blank. The method comprises mounting an ophthalmic lens element blank on a mandrel according to the method of the third aspect. The method may comprise mounting the mandrel (with the blank attached to the mandrel by wax) on a machine tool. For example, the mandrel may be mounted on the machine tool by inserting the stem of the mandrel into a chuck. The method may comprise machining a front surface of the ophthalmic lens element blank. The method may comprise releasing the ophthalmic lens element blank (which may be called an ophthalmic lens element once formed) from the mandrel, for example by melting the wax. The method may comprise performing further finishing steps on the ophthalmic lens element.

[0047] The method may include receiving an ophthalmic lens element blank with a location fit within a front recess of the mandrel.The method may include dispensing wax within a rear recess of the mandrel.

[0048] An ophthalmic lens element blank may have an anterior surface, which becomes the anterior surface when the lens is used on an eye. An ophthalmic lens element blank may have a posterior surface, which becomes the posterior surface when the lens is used on an eye. The posterior surface may have, for example, a concave (bowl-shaped) region surrounded by a flat region. The anterior surface may have, for example, a convex (dome-shaped) region surrounded by a flat region. Either the anterior or posterior surface may be positioned adjacent to the front surface of a mandrel, allowing machining of the other of the anterior or posterior surface. In this context, the surface of the lens element blank adjacent to the front surface of the mandrel is referred to as the posterior surface of the lens element blank, and the other surface of the lens element blank is referred to as the front surface. Thus, the anterior surface of a blank may be referred to as either the anterior or posterior surface at different times, depending on the orientation of the blank on the mandrel. When the anterior surface of the lens element blank is being machined and the posterior surface is adjacent to the anterior surface, the mandrel may have a convex (dome-shaped) surface region. When the front face of the lens element blank is being machined and the rear face is adjacent to the front face, the mandrel may have a concave (bowl-shaped) surface area. Providing a front face that conforms to the shape of the lens element blank being machined may provide improved accuracy in positioning the lens element on the mandrel.

[0049] The method may comprise the steps of holding one of the anterior and posterior faces of a lens element blank against a front surface of a mandrel, applying wax as described in the method of the third aspect, and then machining the other of the anterior and posterior faces (optionally performing any of the steps of the other method described above with the lens element blank mounted on the mandrel in that orientation). The method may comprise removing the lens element blank from the mandrel after machining of its surface is completed. The method may be repeated to machine the other of the anterior and posterior faces of the same lens element blank. The method may comprise the steps of holding the machined one of the anterior and posterior faces of the lens element blank against a front surface of a mandrel, applying wax as described in the method of the third aspect, and then machining the other of the anterior and posterior faces (optionally performing any of the steps of the other method described above with the lens element blank mounted on the mandrel in that orientation). The method may include removing the lens element blank from the mandrel after machining is complete. Thus, the method may provide a method for mounting and / or machining a lens element blank to provide a lens element.

[0050] The method may comprise holding the anterior face of a first lens element blank against the front face of a mandrel, applying wax as described in the method of the third aspect, and then machining the posterior face (optionally performing any of the steps of the other methods described above with the first lens element blank mounted on the mandrel in that orientation). The method may then comprise removing the first lens element blank from the mandrel after machining of its surface is complete. The method may then comprise holding the machined posterior face of the first lens element blank against the front face of a mandrel, applying wax as described in the method of the third aspect, and then machining the other of the anterior and posterior faces. The method may comprise mounting one or more optical components on the first lens element blank, for example, on the front face of the lens element blank. The method may comprise laminating a second lens element blank onto the first lens element blank. The method may then include machining the front face of the second lens element blank while it is affixed to the first lens element blank and thereby held on the mandrel (and optionally performing any of the steps of the other methods described above with the second lens element blank mounted on the mandrel in that orientation), and thus the method may provide a method for mounting and / or machining a lens element assembly.

[0051] Machining can include, for example, cutting on a lathe, polishing, grinding, or any other machining operation in which the lens needs to be held and supported.

[0052] The following paragraphs describe aspects of ophthalmic lenses that relate to any of the above or below described aspects of the present disclosure.

[0053] The ophthalmic lens may include a central optical zone and an annular peripheral zone surrounding the central optical zone, and the first and second regions having wax residue may be disposed within the peripheral zone. The lens may include multiple regions having wax residue spaced apart within the peripheral zone.

[0054] The ophthalmic lens may include one or more optical components, such as a diffractive optical element, and an electrically switchable component including a liquid crystal cell. The ophthalmic lens may include one or more optical components disposed between a first ophthalmic lens element and a second ophthalmic lens element.

[0055] An ophthalmic lens may include an ophthalmic lens element manufactured by machining an ophthalmic lens element blank. An ophthalmic lens may comprise a lens element blank having its front surface (i.e., the front surface when used on an eye) and / or its rear surface (i.e., the rear surface when used on an eye) machined (machined). An ophthalmic lens may include a single lens element blank having its front and / or rear surface machined (machined). Alternatively, an ophthalmic lens may include two (or more) lens element blanks, each having its front and / or rear surface machined (machined). An ophthalmic lens may include a first lens element having its rear surface machined (machined) and a second lens element having its front surface machined (machined). For example, the second lens element is secured to the first lens element, and optionally, one or more optical components are disposed therebetween. In some embodiments, the first and second lens elements define an encapsulation component, itself encapsulated within a lens material to form a lens. In other embodiments, the ophthalmic lens may be formed by only a first lens element and a second lens element.

[0056] The optical zone of the lens element may be centered on the optical axis. The optical axis may be aligned with the center of the lens element. The optical zone of a lens or lens element encompasses the portion of the lens that has an optical function when in use. The optical zone may be configured to be positioned above or in front of the pupil of the eye when in use. In plan view, the lens element may have an optical zone surrounded by a peripheral zone. The peripheral zone is not part of the optical zone but is located outside the optical zone. When the lens element is worn, the peripheral zone may be located above the iris. The peripheral zone may serve a mechanical function, such as increasing the size of the lens element to facilitate lens handling. The peripheral zone may extend to the edge of the lens element. The peripheral zone may provide ballast to prevent rotation of the lens element and / or provide a geometric region that improves comfort for the lens wearer.

[0057] As used herein, an ophthalmic lens may be a spectacle lens or a contact lens. A lens may include one or more lens elements manufactured by machining one or more lens element blanks. A contact lens may include one or more contact lens elements manufactured by machining one or more contact lens element blanks.

[0058] The contact lenses may be hard contact lenses or soft contact lenses, such as hydrogel contact lenses or silicone hydrogel contact lenses. As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the anterior surface of the eye. It will be understood that such contact lenses provide clinically acceptable eye movement and do not constrain a person's eye.

[0059] Contact lenses can be used to correct or improve vision associated with myopia, presbyopia, hyperopia, astigmatism, or other refractive errors. The contact lenses can be soft contact lenses, such as hydrogel contact lenses or silicone hydrogel contact lenses. The contact lenses can be rigid gas-permeable contact lenses. The contact lenses can be scleral contact lenses.

[0060] The contact lens (and thus the contact lens element blank) may comprise an elastomeric material, a silicone elastomeric material, a hydrogel material, or a silicone hydrogel material, or a combination thereof. As understood in the contact lens art, a hydrogel is a material that retains water in equilibrium and does not contain silicone-containing compounds. A silicone hydrogel is a hydrogel that contains silicone-containing compounds. As described in the context of this disclosure, hydrogel and silicone hydrogel materials have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). In some embodiments, hydrogel or silicone hydrogel materials have an EWC of about 30% to about 70% (wt / wt). By comparison, as described in the context of this disclosure, silicone elastomeric materials have a water content of about 0% to less than 10% (wt / wt). Typically, the silicone elastomeric materials used in the present methods or devices have a water content of 0.1% to 3% (wt / wt).Examples of suitable lens formulations (compositions) include those having the following United States Adopted Names (USAN): methafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon A, senofilcon (s enofilcon A, senofilcon B, senofilcon C, narafilcon A, narafilcon B, balafilcon A, samfilcon A, lotrafilcon A, lotrafilcon B, somofilcon A, riofilcon A, delefilcon A, verofilcon A, kalifilcon A, refilcon A, and the like.

[0061] Alternatively, the lens (and thus the lens element blank) may comprise, consist essentially of, or consist of a silicone elastomer material. For example, the lens may comprise, consist essentially of, or consist of a silicone elastomer material having a Shore A hardness of 3 to 50. Shore A hardness may be determined using conventional methods (e.g., using method DIN 53505), as understood by those skilled in the art. Other silicone elastomer materials may be obtained, for example, from NuSil Technology or Dow Chemical Company.

[0062] Alternatively, the lens (and lens element blank) may comprise polymethyl methacrylate (PMMA).

[0063] The contact lens may be substantially circular in shape. The contact lens may have a diameter of 4 mm or more and 20 mm or less, for example, 10 mm or more and 20 mm or less. The optic zone of the contact lens may be substantially circular in shape and may have a diameter of 2 mm or more and 10 mm or less. In some embodiments, the contact lens may have a diameter of 13 mm to 15 mm, and the optic zone may have a diameter of 7 mm to 9 mm. The contact lens may have a convex anterior surface. The contact lens may have a concave posterior surface.

[0064] In a fifth aspect of the present disclosure, a batch of 1000 ophthalmic lenses, e.g., a batch of 1000 contact lenses, is provided. Each lens in the batch can be machined using the mandrel of the first and / or second aspects and / or the method of the third and / or fourth aspects. Each lens can have a central optical zone and an annular peripheral zone surrounding the central optical zone, the central optical zone of each lens being free of wax residue and / or scratches, and at least one of the lenses can have a peripheral zone including a surface with wax residue and / or scratches. The peripheral zone can be an annular peripheral zone.

[0065] Conventional lens processing methods that use wax to hold the lens element on the mandrel result in many lenses with wax residue in the optic zone and / or scratches in the optic zone (which can be caused by removing the wax residue). Known methods that use wax do not result in an error rate of less than 1 in 1000 lenses for these defects. Lenses manufactured using the mandrel of the present disclosure, on the other hand, may avoid such defects by limiting the area where the wax contacts the lens blank to the peripheral zone.

[0066] At least 10 percent, such as at least 20 percent, of the lenses may have an annular peripheral zone that includes a surface with wax residue and / or a scratched surface.

[0067] It will be understood that the lenses of a batch are manufactured sequentially. As used herein, "manufactured sequentially" means that the batch is made up of lenses manufactured one after the other with no intervening lenses that do not form part of the batch.

[0068] As used herein, "wax residue" refers to wax left behind on the surface of a lens / lens element that is visible to the naked eye.

[0069] As used herein, a "blemish" refers to one or more scratches on the surface of a lens or lens element that are visible to the naked eye.

[0070] The regions having wax residues can correspond to the locations of the through-holes when the lens is held against the front surface of the mandrel. The peripheral zone can comprise a surface having a first region having wax residues and a second region having wax residues, the first region being spaced apart from the second region. Each region can correspond to the location of a through-hole.

[0071] Each ophthalmic lens may include a first ophthalmic lens element, a second ophthalmic lens element, and one or more optical components located between the first and second ophthalmic lens elements. The optical zone of each of the first and second lens elements may be free of wax residue and / or scratches. The at least one lens may comprise a first and / or second lens element having an annular peripheral zone including a surface having wax residue and / or a scratched surface.

[0072] In a sixth aspect of the present disclosure, there is provided an ophthalmic lens processed (machined) using the mandrel of the first aspect and / or the second aspect and / or the method of the third aspect and / or the fourth aspect. The lens may comprise a central optical zone and a peripheral zone surrounding the central optical zone. The central optical zone may be free of wax residue and scratches, and the peripheral zone may have wax residue and / or include a scratched surface. The lens of the sixth aspect may have any of the features described above with respect to the fifth aspect (or any other aspect) of the present disclosure.

[0073] 1A, 1B, and 1C, a mandrel 1 according to one embodiment of the present disclosure is illustrated. The mandrel includes a stem 2 and a flange 4 disposed at one end of the stem 2 and extending radially outward from the stem 2. The flange 4 defines a portion of a front surface 6 of the mandrel opposite the flange 4 relative to the stem 2, and a rear surface 8 opposite the flange 4 relative to the front surface 6. Two through-holes 10 extend through the flange 4 between the front surface 6 and the rear surface 8. The through-holes 10 are located on opposite sides of the stem 2 and appear circular when viewed in plan in FIG. 1B. A front recess 12 is defined in the front surface 6 by a rim 14 extending around the flange 4. A rear recess 16 is defined in the rear surface 8 by a rim 18 extending around the flange 4. The through-hole 10 extends between the bottom of the front recess 12 and the bottom of the rear recess 16. The mandrel 1 includes a dome 20 that defines a portion of the anterior surface 6. The dome 20 is concentric with the flange 4 and the stem 2 and is located on the opposite side of the flange 4 from the stem 2. The dome 20 is centered on an optical zone 22 on the anterior surface, and the through-holes 10 are located within an annular peripheral zone 24 outside the optical zone 22. In FIG. 1B, the dashed line indicates the extent of the optical zone 22.

[0074] 1C shows a schematic cross-sectional view of the mandrel 1 of FIG. 1A with a contact lens element assembly 50 secured thereto using wax (not shown). The contact lens element assembly 50 includes a first lens element blank 52 and a second lens element blank 54. The second lens element blank 54 is concentrically mounted on the first lens element blank 52, with a plurality of optical components 56 encapsulated between the first lens element blank 52 and the second lens element blank 54. Each of the first and second lens element blanks 52, 54 includes an optic zone 53 centrally disposed on the lens element and an annular peripheral zone 55 concentrically disposed about and surrounding the optic zone 53. In FIG. 1C, the contact lens element assembly 50 is positioned such that the posterior surface of the first lens element blank 52 abuts the anterior surface 6 of the mandrel 1, and the anterior surface of the second lens element blank 54 becomes the anterior surface 60 of the assembly 50, which can then be machined. Thus, the back surface 58 of the first lens element blank 52 is concave in the optic zone 53 and planar in the peripheral zone 55, thereby conforming to the shape of the front surface 6 defined by the flange 4 and the dome 20. The through-hole 10 is located in the peripheral zone 55. While FIG. 1C and the following embodiments relate to contact lens elements and contact lens element assemblies, it will be understood that other ophthalmic lens elements / lens element assemblies may be machined using the mandrel of the present disclosure. While FIG. 1C illustrates a contact lens element assembly formed by two contact lens elements, it will be understood that the mandrel of the present disclosure may also be used to machine a single contact lens element or a contact lens element assembly formed by more than two lens elements. A batch may include 1,000 contact lenses, each formed by a contact lens element assembly 50 as shown in FIG. 1C.

[0075] In use, wax is dispensed into the posterior recess 16, flows into the through-hole 10, and contacts the posterior surface 58 of the first lens element 52. In this manner, the lens assembly is fixed in place on the mandrel, but the wax contacts the posterior surface 58 only where the through-hole 10 opens into the anterior surface 6. This may allow the location of the wax contacting the lens assembly to be controlled, e.g., confined to non-optical regions of the lens. For example, in FIG. 1C, the through-hole 10 is located in the peripheral zone 55, so any fogging of the lens as a result of the wax does not affect the optic zone 53.

[0076] Referring to Figures 2A, 2B, and 2C, a mandrel 1 according to a second embodiment of the present disclosure is illustrated. Only those aspects of the second embodiment that differ from the first embodiment are described here. Similar reference numerals are used to designate similar elements (e.g., through-holes 10) between the first and second embodiments. In contrast to the first embodiment, the mandrel 1 of the second embodiment has six through-holes 10: four through-holes 10a that appear kidney-shaped in plan view (kidney-shaped through-holes) and two through-holes 10b that appear circular in plan view (circular through-holes). The two circular through-holes 10b are located opposite each other around the anterior recess 12 of the peripheral zone 24 (shown in Figure 2B), and the four kidney-shaped through-holes 10a form two opposing pairs on either side of the peripheral zone 24. The optical zone 22 (shown in Figure 2B) is flat. An annular raised region 60 extends around the outside of the peripheral zone 24, and an annular reservoir 62 extends around the outside of the peripheral zone 24. The annular raised region 60 includes several radially extending channels 64, each extending from a through-hole 10 to the annular reservoir 62.

[0077] In use, excess wax can flow into the annular reservoir via grooves 64 extending radially from the through-hole 10, thereby preventing excess wax from contacting the rear surface of the lens element located on the mandrel.

[0078] 3A, 3B, and 3C illustrate a mandrel 1 according to a third embodiment of the present disclosure. Only those aspects of the third embodiment that differ from the first embodiment are described here. Similar reference numerals are used to indicate similar elements (e.g., through-holes 10) between the first and third embodiments. In contrast to the first embodiment, the mandrel 1 of the third embodiment has three kidney-shaped through-holes 10 evenly spaced around the circumference of the flange 4 within the peripheral zone 24 (shown in FIG. 3B). Similar to the second embodiment, an annular raised region 60 extends around the outside of the peripheral zone 24, and an annular reservoir 62 extends around the outside of the peripheral zone 24. The annular raised region 60 includes three radially extending grooves 64, each extending from the outer edge of the forward recess 12 adjacent one of the through-holes 10 to the annular reservoir 62.

[0079] In use, excess wax may flow to the annular reservoir via grooves 64 extending radially from the through hole 10, thereby reducing the buildup of excess wax in the area of ​​the through hole 10. In the third embodiment, the radially extending grooves 64 are not directly connected to the through hole 10, but may still provide a benefit in terms of reducing contact between the wax and the posterior surface of the lens element outside the area of ​​the through hole 10.

[0080] As more clearly shown in Figure 3C, an axial cavity 66 extends along the length of the mandrel 1. The axial cavity 66 provides a socket into which an adapter 67 including a dome-shaped end 69 may be inserted to define a convex portion of the anterior surface 6 to support a lens element mounted thereon. The provision of the axial cavity 66 may thereby provide a more flexible mandrel that may be reconfigured for use in machining the anterior and posterior surfaces of a lens element blank.

[0081] Figure 4 illustrates a mandrel 1 according to an exemplary embodiment of the present disclosure mounted in a chuck 68 of a lathe (not shown) for cutting with a cutting tool 70. Wax 72 has been filled into the through hole 10 and rear recess 16 and is in contact with the rear surface 58 of the first lens element blank 52 received in the front recess 12. In use, the cutting tool 70 cuts the front surface 74 of the first lens element, which in Figure 4 is the front surface of the lens element. While Figure 4 illustrates the mandrel 1 in a lathe, it will be understood that other machining operations, such as polishing and / or grinding, may be performed using the mandrels of the present disclosure.

[0082] FIG. 5 shows a flowchart of an exemplary method according to the present disclosure. A lens element blank is held against the front surface of a mandrel (100). Next, wax is dispensed onto the rear surface of the mandrel (102) and flows into the through-hole (104), contacting the rear surface of the lens element blank adjacent the front surface of the mandrel. Optionally, the method may include the following additional steps (individually or in combination), which are indicated by dashed lines in FIG. 5: After the wax flows to and contacts the surface of the lens element blank (104), the wax is allowed to harden (108). The blank is then released from its grip, but the lens element blank is still held in place by the wax (110). The mandrel is then mounted in a lathe (or other machine tool) (112), for example, by receiving the stem of the mandrel in the lathe's chuck. The front surface of the lens element blank is then machined (114), for example, cut. The wax is then melted and the lens element blank is removed from the mandrel (116).

[0083] If machining of both the anterior and posterior surfaces of the lens element is required, the above steps are performed so that the anterior surface of the lens element contacts the wax and the posterior surface of the lens element is machined. After the lens element is released from the mandrel (116), the above steps are performed so that the posterior surface of the lens element contacts the wax and the anterior surface of the lens element is machined (or vice versa). The resulting lens element is then sent for finishing. Depending on whether the anterior or posterior surface is machined, reconfiguration of the mandrel (e.g., by changing between different shaped adapters) or a different shaped mandrel may be required to support the lens.

[0084] If a lens element assembly including two lens elements is desired, the aforementioned steps are performed so that the anterior surface of the first lens element contacts the wax and the posterior surface of the first lens element is machined. The method may then include repeating the aforementioned steps 100-110 while the posterior surface of the first lens element blank is held against the front surface of the mandrel. Optionally, steps 112-114 are repeated to machine the anterior surface of the first lens element. An optical component, such as a photoelectric component, is then mounted on the front surface of the first lens element blank. A second lens element blank is then secured to the first lens element blank with its front surface adjacent to the first lens element blank. Steps 112-116 are then repeated to machine the posterior surface of the second lens element blank, and the assembly is removed from the mandrel. The resulting lens element assembly is sent to a finishing process.

[0085] FIG. 6 shows an exploded view of a mandrel 1, a lens element blank 52, a first support 80, and a second support 82 according to one embodiment of the present disclosure. The lens element blank 52 is shown above the first support 80, the top surface of which includes a bowl-shaped cavity 84 corresponding to the shape of the front surface (front face in FIG. 6 ) of the lens element blank 52. The mandrel 1 is shown above the lens element blank 52 with its front surface facing downward, and the second support 82 is shown above the mandrel 1. The bottom surface of the second support 82 includes a cylindrical cavity 84 corresponding to the shape of the mandrel stem. In use, the lens element blank 52 is placed on the first support 80 with the dome of its front surface received within the bowl-shaped cavity 84. The mandrel 1 is then placed over the lens element blank 52, with its front surface abutting the rear surface of the lens element blank 52. Next, a second support 82 is placed over the mandrel 1, with the stem of the mandrel 1 received within the cylindrical cavity 86. Together, the second support 82 and the first support 80 hold the mandrel 1 and lens element blank 52 in alignment while wax is applied to the mandrel 1. In Figure 6, the front face of the lens element blank is shown positioned for machining. It will be appreciated that if the rear face is to be machined, it may be desirable to replace the bowl-shaped cavity 84 with a dome-shaped surface to better support the lens element blank 52.

[0086] 7 shows a photograph of a contact lens element according to an embodiment of the present disclosure. Wax residue 99 is shown in three distinct regions on the peripheral zone of the lens element. For clarity, dashed lines have been added to the photograph to indicate the approximate extent of the regions. FIG. 7 shows a lens element that is combined with a second lens element to form an encapsulated component that is then encapsulated in lens material to form a lens.

[0087] While the present disclosure has been described and illustrated with reference to particular embodiments, it will be understood by those skilled in the art that the present disclosure lends itself to many different variations not specifically illustrated herein.

[0088] Where the foregoing description refers to integers or elements that have known, obvious, or foreseeable equivalents, such equivalents are hereby incorporated by reference as if individually set forth herein. Reference should be made to the claims to determine the true scope of the present disclosure. The claims should be construed to embrace all such equivalents. The reader will also understand that any integers or features of the present disclosure described as preferred, advantageous, convenient, or the like are optional and do not limit the scope of the independent claims. Furthermore, it should be understood that such optional integers or features may be beneficial in some embodiments of the present disclosure, but may be undesirable in other embodiments and, therefore, may not be present in other embodiments. The claims at the time of filing are as follows: [Claim 1] 1. A mandrel for holding an ophthalmic lens member blank during processing, comprising: a front surface for receiving an ophthalmic lens element blank to be machined; a rear surface opposite to the front surface; one or more through holes extending between the front surface and the rear surface; Equipped with In use, wax applied to the rear surface contacts an ophthalmic lens element blank received in the front surface through the one or more through holes. A mandrel characterized by: [Claim 2] the anterior surface includes a central optical zone and an annular peripheral zone; the one or more through holes are located within the peripheral zone 2. The mandrel of claim 1. [Claim 3] The front surface of the mandrel is convex, concave, or flat within the optical zone. 3. The mandrel of claim 2. [Claim 4] a stem for attaching the mandrel to a machine tool; a flange extending radially from the stem; Equipped with the flange having the front surface, the rear surface, and the one or more through holes; 4. A mandrel according to claim 1, wherein the mandrel is a tubular member. [Claim 5] The mandrel has a longitudinal axis and a plurality of through holes circumferentially spaced about the longitudinal axis. 5. A mandrel according to claim 1. [Claim 6] The through holes are equally spaced about the longitudinal axis. 6. The mandrel of claim 5. [Claim 7] the anterior surface has an anterior recess shaped to receive, e.g., by positional fitting, the ophthalmic lens element blank; 7. A mandrel according to any one of claims 1 to 6. [Claim 8] The rear surface has a rear recess, for example an annular recess. 8. A mandrel according to any one of claims 1 to 7. [Claim 9] Each through hole has a first opening on the front surface and a second opening on the rear surface; Optionally, the first opening is located in the front recess, and / or the second opening is located in the rear recess. 9. The mandrel according to claim 7 or 8. [Claim 10] the front surface has a raised annular region defining the forward recess and an annular reservoir located radially outward of the raised region; The reservoir is connected to the front recess by one or more drainage channels, allowing excess wax in the front recess to flow through the drainage channels to the reservoir. 10. The mandrel of claim 9. [Claim 11] the through hole has a longitudinal axis; The through-holes, when viewed in cross section perpendicular to the longitudinal axis, are substantially circular, kidney-shaped, and / or arc-shaped, e.g., arc-shaped having a constant radius relative to the center of the front surface. 11. A mandrel according to any one of claims 1 to 10. [Claim 12] The lens element blank is a contact lens element blank, for example, a contact lens element blank for a soft contact lens such as a hydrogel contact lens or a silicone hydrogel contact lens, or a rigid gas-permeable contact lens. 12. A mandrel according to any one of claims 1 to 11. [Claim 13] A kit of parts comprising a mandrel according to any one of claims 1 to 12, the mandrel has a socket in the front face for receiving an adapter; Contains one or more of the following: A parts kit featuring: an adapter having a convex end configured to be received within the socket such that the convex end defines a portion of the front surface of the mandrel; an adapter having a concave end configured to be received within the socket such that the concave end defines a portion of the front surface of the mandrel; An adapter having a flat end configured to be received within the socket such that the flat end defines a portion of the front face of the mandrel. [Claim 14] 1. A method of mounting an ophthalmic lens element blank, such as a contact lens element blank, on a mandrel, comprising: the mandrel has a front surface, a rear surface, and one or more through holes extending between the front surface and the rear surface; The method comprises: holding the ophthalmic lens element blank against the front surface of the mandrel; applying wax to the rear surface of the mandrel while the ophthalmic lens element blank is held against the front surface of the mandrel; the wax flows through the one or more through-holes and contacts the posterior surface of the ophthalmic lens element blank at the through-holes. A method comprising: [Claim 15] the ophthalmic lens element blank is conformally received within a front recess formed in the front surface of the mandrel; the wax is dispensed into a rear recess formed in the rear surface of the mandrel; The one or more through holes extend between the front recess and the rear recess. 15. The method of claim 14. [Claim 16] 1. A method of fabricating an ophthalmic lens member blank, comprising: Mounting the ophthalmic lens element blank on a mandrel according to the method of claim 14 or 15; releasing the hold so that the lens element blank is held on the mandrel by the wax; machining a front surface of the ophthalmic lens element blank while the lens element blank is held on the mandrel; A method comprising: [Claim 17] While holding a first ophthalmic lens element blank against said anterior surface: applying wax to the rear surface of the mandrel, the wax flowing through the one or more through holes and contacting the rear surface of the ophthalmic lens element blank at the through holes; Including, While the first ophthalmic lens element blank is held on the mandrel by the wax, mounting one or more optical components onto said first ophthalmic lens member blank; securing a second ophthalmic lens element blank to the first ophthalmic lens element blank, wherein the optical component is positioned between the first ophthalmic lens element blank and the second ophthalmic lens element blank; machining the front surface of the second lens member blank; Contains 17. The method of claim 16. [Claim 18] A batch of 1000 ophthalmic lenses, each lens being machined using a mandrel according to any one of claims 1 to 13 and / or manufactured using a method according to any one of claims 14 to 17; Each lens comprises a central optical zone and a peripheral zone surrounding the central optical zone; the central optical zone of each lens is free of wax residue and scratches; At least one of the lenses has a peripheral zone that includes a surface with wax residue and / or scratches. A batch characterized by: [Claim 19] Each ophthalmic lens includes a first ophthalmic lens element, a second ophthalmic lens element, and one or more optical components disposed between the first ophthalmic lens element and the second ophthalmic lens element. 19. The batch according to claim 18. [Claim 20] Each lens is a contact lens, e.g., a soft contact lens such as a hydrogel contact lens or a silicone hydrogel contact lens, or a rigid gas permeable contact lens. 20. A batch according to claim 18 or 19. [Claim 21] An ophthalmic lens processed using a mandrel according to any one of claims 1 to 13 and / or manufactured using a method according to any one of claims 14 to 17, The lens comprises a central optical zone and a peripheral zone surrounding the central optical zone; the central optical zone is free of wax residue and scratches; The peripheral zone comprises a surface with wax residue and / or scratches. An ophthalmic lens characterized by:

Claims

1. 1. A mandrel for holding an ophthalmic lens member blank during processing, comprising: a front surface for receiving an ophthalmic lens element blank to be machined; a rear surface opposite to the front surface; one or more through holes extending between the front surface and the rear surface; Equipped with wherein, in use, wax applied to the posterior surface contacts an ophthalmic lens element blank received on the anterior surface through the one or more through holes; The mandrel is a stem for attaching the mandrel to a machine tool; a flange extending radially from the stem; Further provided with the flange having the front surface, the rear surface, and the one or more through holes; the anterior surface includes a central optical zone and an annular peripheral zone; The one or more through holes are located within the annular peripheral zone. A mandrel characterized by:

2. The front surface of the mandrel is convex, concave, or flat within the central optical zone.

2. The mandrel of claim 1.

3. The mandrel has a longitudinal axis and a plurality of through holes circumferentially spaced about the longitudinal axis.

3. The mandrel according to claim 1 or 2.

4. The through holes are equally spaced about the longitudinal axis.

4. The mandrel of claim 3.

5. The anterior surface has an anterior recess shaped to receive the ophthalmic lens element blank.

3. The mandrel according to claim 1 or 2.

6. The rear surface has a rear recess.

3. The mandrel according to claim 1 or 2.

7. The rear surface has a rear recess, Each through hole has a first opening on the front surface and a second opening on the rear surface; Optionally, said first opening is located in said front recess, and / or said second opening is located in said rear recess.

6. The mandrel of claim 5.

8. the front surface has a raised annular region defining the forward recess and an annular reservoir located radially outward of the raised annular region; The annular reservoir is connected to the front recess by one or more drainage channels, allowing excess wax in the front recess to flow through the drainage channels to the annular reservoir.

8. The mandrel of claim 7.

9. the through hole has a longitudinal axis; The through-holes are circular, kidney-shaped, and / or arc-shaped when viewed in cross section perpendicular to the longitudinal axis.

3. The mandrel according to claim 1 or 2.

10. The ophthalmic lens element blank is a contact lens element blank.

3. The mandrel according to claim 1 or 2.

11. A kit of parts comprising the mandrel of claim 1 or 2, the mandrel has a socket in the front face for receiving an adapter; Contains one or more of the following: A parts kit characterized by: an adapter having a convex end configured to be received within the socket such that the convex end defines a portion of the front surface of the mandrel; an adapter having a concave end configured to be received within the socket such that the concave end defines a portion of the front surface of the mandrel; An adapter having a flat end configured to be received within the socket such that the flat end defines a portion of the front face of the mandrel.

12. 1. A method of mounting an ophthalmic lens element blank on a mandrel, comprising: the mandrel has a front surface, a rear surface, and one or more through holes extending between the front surface and the rear surface; The mandrel further includes a stem for mounting the mandrel to a machine tool and a flange extending radially from the stem; the flange having the front surface, the rear surface, and the one or more through holes; the anterior surface includes a central optical zone and an annular peripheral zone; the one or more through holes are located within the annular peripheral zone; The method comprises: holding the ophthalmic lens element blank against the front surface of the mandrel; applying wax to the rear surface of the mandrel while the ophthalmic lens element blank is held against the front surface of the mandrel; the wax flows through the one or more through-holes and contacts the posterior surface of the ophthalmic lens element blank at the through-holes. A method comprising:

13. the ophthalmic lens element blank is conformally received within a front recess formed in the front surface of the mandrel; the wax is dispensed into a rear recess formed in the rear surface of the mandrel; The one or more through holes extend between the front recess and the rear recess.

13. The method of claim 12.

14. 1. A method of fabricating an ophthalmic lens member blank, comprising: Mounting the ophthalmic lens element blank on a mandrel according to the method of claim 12 or 13; releasing the hold so that the ophthalmic lens element blank is held on the mandrel by the wax; machining a front surface of the ophthalmic lens element blank while the ophthalmic lens element blank is held on the mandrel; A method comprising:

15. While holding a first ophthalmic lens element blank against said front surface: applying wax to the rear surface of the mandrel, the wax flowing through the one or more through holes and contacting the rear surface of the ophthalmic lens element blank at the through holes; Including, While the first ophthalmic lens element blank is held on the mandrel by the wax, Mounting one or more optical components on said first ophthalmic lens element blank; securing a second ophthalmic lens element blank to the first ophthalmic lens element blank, wherein the optical component is positioned between the first ophthalmic lens element blank and the second ophthalmic lens element blank; machining the front surface of the second ophthalmic lens element blank; Contains 15. The method of claim 14.

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