Lens for eyewear and other head-worn support means having improved optics

Abstract

To provide a lens that has an improved optical configuration in order to provide enhanced off-axis optical performance by contributing to reducing, eliminating or minimizing first order optical distortion.SOLUTION: Embodiments may be used in non-corrective or corrective unitary or dual lens eyewear, e.g., in combination with a frame to support the lens in a path of a straight ahead line of sight forming a center axis of an eye of a typical wearer. The lens comprises a lens body 602. The lens body 602 may comprise a surface having a spherical, toric, cylindrical or freeform geometry, and another surface having a freeform geometry. A lens thickness 616 is defined between the surfaces. A prismatic power of the lens is improved, particularly for off-axis viewing angles.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] Embodiments of the present invention generally relate to lenses for eyewear, and more particularly to uniquely configured lenses having improved off-axis optical performance that sometimes results in the reduction, minimization, or elimination of prism shift, also referred to as prism effect, refractive power, aberration, or distortion. Such lenses can be used, for example, in intense sports or as fashion sunglasses. These embodiments of eyewear designs achieve various functional advantages, such as maximizing the blocking of peripheral light, reducing optical distortion, and increasing the wearer's comfort level compared to conventional eyewear.

Background Art

[0002] In a single lens system, a full field of view from side to side and good lateral eye protection are provided, but current prior art still addresses the problem of optical distortion. In a single lens system, for example, the angle of incidence of a line from the wearer's eye to the rear lens surface changes as the wearer's line of sight moves in a direction herein referred to as the "off-axis" direction to any angle with respect to the forward direct line of sight. The off-axis direction can be, for example, horizontal, vertical, or a combination thereof. As a result, the refraction between light incident closer to the front of the lens and peripheral light incident at the off-axis portion of the lens will be different. The disclosure of U.S. Patent No. 4,859,048 is an example of an attempt to address this cause of prism distortion by making the lens thickness thinner from the middle portion towards the lateral edge. Another example is U.S. Patent No. 5,969,789.

[0003] A dual lens system has been developed in which the lateral edges of each lens curve rearward from the front plane along the side of the wearer's head, providing a lateral wrap similar to that achieved by a high curve single lens system. While large-wrap dual lens glasses provide some protection to the sides of the eyes, the curvature of the lenses generally results in measurable prism distortion aberration through the angular range of the wearer's field of view. This is particularly pronounced in lenses containing high refractive index materials. In addition, in order to optimize the wrap while maintaining a low profile, a high base curve curvature (e.g., 6 curves or more) is sometimes desirable, but such lenses utilize a lathe cut surface shape and have not been optically optimal heretofore due to a relatively high level of prism distortion aberration at off-axis viewing angles.

SUMMARY OF THE INVENTION

MEANS FOR SOLVING THE PROBLEM

[0004] In one embodiment, a lens for use in combination with a frame for supporting the lens within the path of the forward line of sight that forms the central axis of one eye of a typical wearer in non-corrective dual lens eyewear or headgear includes a lens body. In one embodiment, the lens body includes a front surface having a spherical, toric, cylindrical, or freeform shape. In one embodiment, the lens body includes a rear surface having a freeform shape. In one embodiment, the lens thickness is defined between the front and rear surfaces. In one embodiment, the visual axis extends at an angle from the one eye and the central axis, measured along the horizontal meridian of the rear surface, away from the central axis from the nose of a typical wearer. In one embodiment, each point along the horizontal meridian of the rear surface is associated with the angle of the visual axis at the position where the visual axis intersects each point along the horizontal meridian of the rear surface. In one embodiment, the prism refractive power of the lens is 0.25 diopters or less across the points along the horizontal meridian of the rear surface that are associated with angles of the visual axis of about 30 degrees or less.

[0005] In one embodiment, a single lens for use in combination with a frame for supporting the lens within the paths of the left and right front direct vision lines that form the left central axis of the left eye and the right central axis of the right eye of a typical user, respectively, in non-corrective eyewear or headgear, includes a lens body. In one embodiment, the lens body includes a front surface having a spherical, toric, cylindrical, or freeform shape. In one embodiment, the lens body includes a rear surface having a freeform shape. In one embodiment, the lens thickness is defined between the front surface and the rear surface. In one embodiment, the left visual axis extends at an angle relative to the left central axis, measured from the left eye and the left central axis, away from the nose of a typical wearer, along the horizontal meridian of the rear surface. In one embodiment, each of the first points along the horizontal meridian of the rear surface is associated with an angle of the left visual axis at the position where the left visual angle intersects each of the first points along the horizontal meridian of the rear surface. In one embodiment, the prism refractive power of the single lens is 0.23 diopters or less through the entirety of the first points along the horizontal meridian of the rear surface, associated with an angle of the left visual axis of about 30 degrees or less.

[0006] In one embodiment, a method of designing a lens for non-corrective eyewear or headgear includes generating a point mesh of an initial front surface of the lens. In one embodiment, the method includes generating a point mesh of a freeform back surface of the lens based on the initial front surface. In one embodiment, points of the point mesh of the freeform back surface correspond to points of the point mesh of the initial front surface. In one embodiment, the method includes identifying a forward visual axis for the lens based on a wearing position of the lens relative to the eyes of a typical wearer. In one embodiment, the method includes identifying a seed point on the initial front surface. In one embodiment, the seed point is a starting reference for subsequent iterative calculations. In one embodiment, the method includes assigning an initial thickness at the seed point. In one embodiment, the method includes calculating a surface normal of a first point on the freeform back surface corresponding to the seed point. In one embodiment, the method includes placing a first point on the freeform back surface according to the initial thickness and refraction of a ray intersecting the seed point from the surface normal to the freeform back surface. In one embodiment, the method includes calculating a surface normal at a point adjacent to the first point on the freeform back surface corresponding to a point adjacent to the seed point in the point mesh of the initial front surface. In one embodiment, the method includes calculating the thickness of a point adjacent to the seed point using an optimization algorithm. In one embodiment, the optimization algorithm includes calculating the refraction of a ray based on the calculated surface normal at a point adjacent to the first point on the freeform back surface. In one embodiment, the method includes placing a point adjacent to the first point on the freeform back surface according to the calculated thickness of the point adjacent to the seed point. In one embodiment, the method includes placing additional points on the freeform back surface by iterative calculation of surface normals and thicknesses of points adjacent to the placed points.

[0007] A method of designing a lens according to an embodiment of the present invention is also disclosed.

[0008] Other features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments, taken in conjunction with the appended claims and drawings.

Brief Description of the Drawings

[0009]

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[0010] In the following, preferred embodiments are discussed with respect to lenses having a "freeform" shape (e.g., a shape other than spherical, toric, planar or cylindrical) for the front and / or rear surfaces, but it should be understood that the present invention can also be applied to lenses having a combination of freeform surfaces and ground surfaces. In addition, it should be understood that the embodiments of the present disclosure can be used not only for the lenses exemplified herein, but also for lenses having many front shapes and orientations in the wearing position. Further, the term "actual angular optical effect" refers to the correction for off-axis rays that minimizes optical distortion aberration from the wearer's perspective as compared to a standard ground surface lens.

[0011] References to the described embodiments and to "one embodiment", "an embodiment", "a preferred embodiment", etc. in this specification indicate that the described embodiments may include a particular feature, structure or characteristic, but not every embodiment necessarily includes that particular feature, structure or characteristic. Further, such phrases do not necessarily refer to the same embodiment. Further, if a particular feature, structure or characteristic is described in connection with an embodiment, it will be understood that such feature, structure or characteristic can be implemented with respect to other embodiments, whether or not explicitly described, within the knowledge of those skilled in the art.

[0012] As used herein, the term "lens" is used to broadly refer to optical components. For example, eyeglass / sunglass lenses, vision shields, visors, etc. are included in the terms "lens" or "lenses for eyewear". As used herein, the term "non-corrective" indicates the absence of the optical power known for prescription lenses.

[0013] Spatially relative terms such as "lower", "below", "bottom", "upper", "above", "top", etc. are used herein for ease of explanation when describing the relationship of one element or feature to another element or feature shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in addition to or instead of the orientation depicted in the figures. For example, the device can be in a different orientation and the spatially relative terms used herein can be interpreted accordingly as well.

[0014] As used herein, terms such as "about", "approximately" indicate a value of a quantity that can vary based on a particular manner. Based on that particular manner, terms such as "about" can indicate a value of a quantity that varies, for example, within 0 to 10% of that value (e.g., ±0.5%, ±5% or ±10% of that value).

[0015] As used herein, terms such as "typical wearer", "typical user" can refer to an average user in general, an average user based on demographics, or a user having body dimensions that conform to a standard or well-known anthropometric database. For example, a typical eyewear wearer can be a person having body dimensions that conform to European standards (EN), American National Standards Institute (ANSI), or anthropometric surveys.

[0016] In addition, certain embodiments are disclosed or may be shown with respect to certain types of eyewear, such as single-lens glasses, dual-lens glasses, glasses with a partial or full or no rim, goggles, sunglasses, wire-frame eyewear, eyewear with only partial wire, rimless eyewear, etc., but it should be understood that embodiments of the present disclosure can be used with any type of head-mounted support means. For example, lens embodiments can be integrated into or attached to headgear products, such as bicycle, skateboard, snow, flight, sports, or other types of helmets with vision shields, visors, hats, headbands, face masks, balaclavas, breathing shields, etc., any head-mounted product that can support one or more lenses within the wearer's field of view. In some embodiments, the lens can be removable from the head-mounted product, thereby allowing the lens to be removed or replaced without damaging the head-mounted product.

[0017] Some method and system embodiments of the present disclosure can be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the present disclosure can also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. The machine-readable medium can include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, the machine-readable medium can include read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, electrical, optical, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Further, firmware, software, routines, and / or instructions can be described herein as performing certain operations. However, such descriptions are for convenience only, and such operations are actually the result of a computing device, processor, controller, or other device executing firmware, software, routines, instructions, etc.

[0018] Despite numerous improvements to eyewear lenses, there remains a need for lenses that have excellent optical quality, reduce optical distortion aberrations, and at the same time enable proper ventilation, maximum comfort and safety for the wearer and / or attachment to a particular headgear. Further, there is a need for lenses for use in eyewear that can substantially block light over the entire angular range of the field of view and at the same time minimize optical distortion aberrations throughout that range.

[0019] However, before describing such embodiments in more detail, it is beneficial to present exemplary metrics in embodiments in which the present disclosure may be characterized and implemented.

[0020] Exemplary Measurement of Optical Performance FIG. 1 is a schematic diagram of an exemplary prism diopter measuring device 100. In one embodiment Then, the prism refractive power measuring device 100 includes a sample mounting base 102 and a collimated radiation source 104 (e.g., a laser) configured to output a collimated radiation beam 106. In certain embodiments, the sample mounting base 102 is configured to support a device under test (DUT) 108 (e.g., a lens, eyewear, or visor). In certain embodiments, the sample mounting base 102 is configured to be adjustable, and the adjustment includes movement along or parallel to the horizontal axis 114, vertical axis 112, and forward line of sight axis 110 and rotation around or with respect to the horizontal axis 110, vertical axis 112, and forward line of sight axis 114. In certain embodiments, the collimated radiation source 104 is structurally independent of the sample mounting base 102, whereby the collimated radiation source 104 remains stationary during adjustment of the sample mounting base 102. It should be understood that the horizontal axis 114 and the vertical axis 112 are perpendicular and parallel, respectively, to the midline passing through the body of a user who may wear the DUT 108, and both the horizontal axis 114 and the vertical axis 112 are perpendicular to the forward line of sight axis 110. Also, it should be understood that the DUT 108, in the case of a lens, has a surface generally referred to as the rear surface that faces the user when worn by the wearer and a surface generally referred to as the front surface that faces away from the user.

[0021] In certain embodiments, the measuring device 100 includes a measurement target 116. The measurement target 116 includes concentric markers (not shown) configured to quantify the prism refractive power of the DUT 108 by measuring the deflection of the collimated beam 106 transmitted through the DUT 108 for different positions and rotations of the DUT 108. In this embodiment, the measurement target 116 is configured to have a fixed position and orientation with respect to the collimated radiation source 104. The measurement of the deflection of the collimated beam 106 transmitted through the DUT 108 is made with respect to a zero deflection state without the DUT 108.

[0022] FIG. 2 is a schematic view of a target 200 used in a prism refractive power measuring apparatus according to an exemplary embodiment. In one embodiment, the target 200 includes concentric circle markers 202 having different radii. In one embodiment, the target 200 includes a horizontal axis marker 204 and a vertical axis marker 204, which intersect at the center of the concentric circle markers 202.

[0023] The measured value of the prism refractive power (the refractive power induced by the lens that causes the displacement of the image) can also be calculated through computer simulation to support the measured value and / or to test the design of a new lens before starting production. Other physical test methods, such as ANSI certification test methods, etc., can be used.

[0024] The following table shows the measured and simulated prism refractive powers of various conventional lenses with various base curves compared to the lenses of the present invention having the "actual angle optical system" shape described with respect to the embodiments of the present disclosure. As conventional lenses described herein, in some examples, conventional lenses that can be corrected only for forward viewing are included. The measurements and simulations are directed towards a typical user's eye and quantify the deviation of the light rays passing through the lens. For example, Table 1 shows the measured values for an exemplary conventional lens 1 (a 4-curve lens for dual lens eyewear) that quantify the displacement of the image induced by the conventional lens 1. The data column labeled "off-axis viewing angle" is the off-axis viewing direction measured with respect to the forward direct line of sight towards the horizontal lateral periphery (horizontal) and the upper periphery (vertical), and the unit is degrees. For the horizontal off-axis viewing angle, a positive angle indicates the line of sight direction when the eye closest to the user's temple during measurement, for example, when the right eye is directed towards the right temple or the left eye is directed towards the left temple. Conversely, a negative horizontal off-axis viewing angle indicates the line of sight direction of the eye directed towards the user's nose. The measurements and simulations described herein are made from the perspective of the user's right eye. A person skilled in the art will appreciate that for the measurements and simulations of the left eye, in the case of a typical user with a substantially symmetric facial structure, the results will be substantially the same and reversed It will be understood that the visual axis angles in all the tables in this specification are within the actual visual fields of different lenses depending on the lenses. For example, the conventional lenses 1 to 4 have a visible range of up to about 40 to 55 degrees until the field of view is blocked by the frame supporting the lens towards the temple closest to the eye during measurement / simulation, and according to the vision shield, horizontal vision up to about 105 degrees of the eye's peripheral limit may be possible, but here it was measured up to about 90 degrees. Quantification of the visual axis angle (negative angle) towards the user's nose, for example in lens 2, does not take into account the shielding by the user's nose, but those skilled in the art will understand that the visible range towards the user's nose is likely to be limited by the shielding by the nose rather than the frame supporting the lens. The actual angle optical system method described in the embodiments of the present disclosure for correcting prism refractive power may similarly or alternatively be applied to the viewing angle towards the upper and lower peripheries of the lens or any off-axis angle (for example, any combination of horizontal and vertical viewing angles of non-zero angles with respect to the forward line of sight, that is, any combination of X and Y displacements). Table 1 shows the prism refractive power of an exemplary conventional lens 1 measured in units of diopters, and the horizontal and vertical displacements of the image produced by the conventional lens 1 are quantified as prism refractive powers X and Y respectively, and the values are preferably closer to 0. The overall prism refractive power R of the conventional lens 1 is [Number] calculated as. Table 1 also shows a metric alternative to the prism refractive power, which is the horizontal component θ X of the angular displacement of the incident light ray produced by the lens and the vertical component θ Y of the angular displacement of the incident light ray produced by the lens. Both are in degrees, and the values are preferably closer to 0. Table 1 shows a third alternative metric for quantifying the displacement of the image produced by the lens, which is the apparent horizontal displacement D X of an object placed about 100 yards away from the wearer and the apparent vertical displacement D Yand the value is preferably closer to 0. The overall apparent displacement D of an object placed about 100 yards away from the wearer R is [Number] is calculated as.

[0025] All data tables of the present disclosure use the organizational scheme, labels, and calculations for the derived data utilized in Table 1.

[0026] In Table 2, a simulation of a redesigned conventional lens 1 adopting an embodiment of the present disclosure is provided for comparison with the measurement results of the original conventional lens of Table 1. The results in Table 2 show a remarkable improvement in the optical performance by simulation (for example, a decrease in the overall prism refractive power) when the actual angle optical system method of the present disclosure is applied to the rear surface of the lens. The maximum decrease from 0.61 to 0.36 diopter in the overall prism refractive power (about halved) is obtained at the measured maximum horizontal visual axis angle of 55 degrees.

[0027] Table 3 shows the prism refractive power by simulation of an exemplary conventional lens 2 having a toric 4×6 shape (about 4 curves vertically and about 6 curves horizontally), and Table 4 shows the prism refractive power by simulation of a redesigned conventional lens 2 adopting an embodiment of the present disclosure on the rear surface. Similar to the data of the conventional lens 1, the overall prism refractive power of the redesigned conventional lens 2 is from 0.91 to 0. 52 diopter at the measured maximum horizontal visual axis angle of 50 degrees compared to the original conventional lens 2. Table 3 is based on a 4×6 single lens, but the dual-lens 4×6 toric design is similarly optimized and improvements similar to those of lenses with a higher base curve can be achieved (for example, the performance of such a toric design may exhibit the same or similar performance as that shown in Table 8 for an 8.75-curve lens).

[0028] For higher base curves, Table 5 shows the measured prism refractive powers of an exemplary conventional lens 3, which is a single lens for wraparound eyewear with a large degree of wrap, e.g., greater than about 6.5 curves. Table 6 shows the measured prism refractive powers of an exemplary conventional lens 4, which has a base curve of 8.75 and is a lens for dual-lens eyewear. Table 7 shows the prism refractive powers of conventional lens 4 by simulation to confirm that the simulation and the actual measurement are in good agreement. When the embodiments of the present disclosure are applied to conventional lens 4, the prism refractive power of conventional lens 4 is dramatically reduced, as shown in FIG. 8. FIG. 8 shows that the overall prism refractive power of the redesigned conventional lens 4 decreased from 1.02 to 0.21 diopters at the measured maximum horizontal visual axis angle of 50 degrees compared to the original conventional lens 4. This is a reduction to about one-fifth of the overall prism refractive power.

[0029] Another improvement in peripheral vision fidelity was measured for an actual freeform vision shield used in protective headgear (e.g., a football helmet) manufactured using embodiments of the present disclosure. This vision shield is a complete freeform and has a freeform front surface and a corresponding freeform back surface, resulting in what is referred to herein as an "actual angle optical profile". The measured data regarding the prism refractive power of the vision shield are shown in Table 9. In this vision shield, the overall prism refractive power is maintained at 0.25 diopters or less over all horizontal visual axis angles up to 90 degrees.

[0030]

Table 1

[0031]

Table 2

[0032]

Table 3

[0033]

Table 4

[0034]

Table 5

[0035]

Table 6

[0036]

Table 7

[0037]

Table 8

[0038]

Table 9

[0039] Exemplary design method for freeform lenses for eyewear to generate a real angle optical effect The method steps will be described with reference to the corresponding flow diagrams. It should be understood that not all steps in the flow diagrams are required to implement the method provided herein. Further, some of the steps may be performed simultaneously or in an order different from that shown in the flow diagrams.

[0040] FIG. 3 shows a general procedure for designing a freeform lens for eyewear that generates a real-angle optical effect (also referred to herein as the "real-angle optical system method") according to an exemplary embodiment. In one embodiment, an initial front surface design is generated at step 310. The initial front surface can be configured to conform to a support structure (e.g., an eyewear frame or protective headgear). The initial front surface can include a lathe cut surface design and / or a freeform design where sufficient prism power reduction is not performed. In one embodiment, the initial front surface design is provided as a 3D calculation formula from which a point mesh or points (e.g., points that are solutions of the 3D calculation formula) can be derived. Since the point mesh can be configured to have a certain pitch (the center-to-center distance between points), it should be understood that the resulting lens will appear smooth and continuous to the wearer. In one embodiment, the point mesh is configured to have a pitch that is not recognizable by a typical user's eye, e.g., less than about 10 μm. It should be understood that the initial front surface can include a lathe cut surface or other existing solutions that may or may not initially result in sufficient prism power reduction for the optical product. At step 312, a freeform back surface design for the eyewear lens is generated based on a calculation of light refraction that takes into account the initial front surface design in order to produce a real-angle optical effect from the perspective of the wearer of the optical system. Optionally, at step 314, a freeform front surface design for the eyewear lens is generated based on a calculation of light refraction that takes into account the back surface design. This freeform front surface replaces the initial front surface and can provide much more accurate distortion aberration correction.

[0041] Figure 4 shows a procedure for generating a freeform back surface design of an eyewear lens to obtain an actual angular optical effect as viewed from the wearer's perspective according to an exemplary embodiment. It should be understood that step 312 (FIG. 3) may include the procedure described herein with respect to FIG. 4. In one embodiment, at step 410, for an initial front surface, such as the initial front surface identified at step 310 (FIG. 3), a central axis corresponding to the wearer's forward line of sight is identified. The forward line of sight axis may depend on the position of the optical system with respect to the user's eye and the user's expected viewing posture. The expected position of the optical system and the expected viewing posture with respect to a typical wearer's eye may vary depending on the type of eyewear and the wearer's activity (e.g., football helmet, motorcycle helmet, aircraft pilot's helmet, bike head-up or golf or fishing head-down display), and these may be derived from actual measurements or computer simulations performed on the test subject.

[0042] At step 412, a portion of the initial front surface for optimization according to various optical solutions is identified. In one embodiment, the optical problem solving may include a central axis (also referred to as "all vectors forward") viewing solution, an off-axis viewing solution, and a solution outside the actual field of view (FOV). Off-axis viewing includes viewing in a line of sight direction that is substantially different from the forward viewing direction, such as through the side of the visor. In one embodiment, the initial front surface is divided into a central portion, a transition portion, and a side portion. The transition portion connects the central portion and the side portion. In one embodiment, the central portion is associated with the forward viewing solution, the side portion is associated with the off-axis viewing solution, and the transition portion provides a smooth and gradual transition between the forward viewing solution and the off-axis viewing solution. In one embodiment, the forward viewing solution may include binocular viewing considerations, and the off-axis solution may include monocular (single-eye) viewing considerations. In one embodiment, the transition boundary between the binocular and monocular solutions is where the off-axis viewing angle increases and the single It can be placed at a location where the wearer's line of sight is blocked by the nose of a typical wearer (i.e., at this boundary, the appearance of the wearer is monocular vision). A person skilled in the art will understand that although the description in this specification relates to a lateral position or direction, embodiments of the present invention are applicable equally to improving distortion aberration in any off-axis direction, such as an off-vertical axis direction or the line-of-sight direction of other non-front / non-frontal direct lines of sight (e.g., any combination of horizontal and vertical viewing angles other than 0 degrees with respect to the frontal direct line of sight, i.e., any combination of horizontal and vertical image displacements).

[0043] In step 414, a seed point on the initial front surface is identified. In some embodiments, the seed point serves as a starting reference point for generating a point on the freeform rear surface. In some embodiments, an initial thickness is assigned to the seed point. In some embodiments, the seed point is selected from the point mesh of the initial front surface design (e.g., step 310 in FIG. 3). In some embodiments, the seed point lies on a symmetry plane that refers to the horizontal symmetry of the optical system. In some embodiments, the seed point lies on a line that refers to the boundary between the central portion and the transition portion or the boundary between the transition portion and the lateral portion. In some embodiments, the seed point is located at the position where the frontal direct line of sight of a typical wearer passes through the initial front surface. In some embodiments, the seed point is not selected from the point mesh and / or can be a point between mesh points.

[0044] In step 416, the surface normal at the seed point is calculated, and the first freeform back point is placed at the initial thickness on the line that coincides with the surface normal at the seed point. It should be understood that each point on the initial front surface is associated with a corresponding point on the freeform back surface, and surface normals and thicknesses must also be assigned to points on the freeform back surface other than the first back point. In step 418, for the points adjacent to the first back point, the surface normals are calculated. In the case of the "all vectors forward" solution, a ray of light parallel to the wearer's forward line of sight that is incident on the front surface generally refracts in a direction not parallel to the forward line of sight within the lens thickness, and the back surface normal for each ray is calculated such that the ray is returned to be parallel to the forward line of sight when it exits the lens back surface. Further, in the case of the "off-axis" solution, a ray of light directed towards the wearer's eye that is incident on the front surface generally refracts in a direction not towards the wearer's eye within the lens thickness, and the back surface normal for each ray is calculated such that the ray is re-directed towards the wearer's eye when it exits the lens back surface. Those skilled in the art will understand that the path of the ray of light passing through the lens depends on the lens thickness at that point and the refractive index of the specific lens material used, and that the thickness and the refractive index of the material are taken into account in the calculation of the surface normal. For example, a polycarbonate lens typically has a refractive index of 1.58 + / - 0.015. As will be described below, other materials and composite materials can be used for the lens, whereby different refractive indices are used in the calculation. In step 420, the optimization algorithm assigns thicknesses to the points adjacent to the first back point and places them at the thickness assigned to at least one of their adjacent points. In one embodiment, the optimization algorithm follows a priority order including a solution with the most uniform optical path length, a solution that makes it as thin as possible, and a solution with the most uniform thickness, whereby the optimization algorithm outputs a surface normal that is substantially the same as that calculated in step 418.

[0045] In some embodiments, the lens may also be designed to conform to other structures, such as the contours of the face, such as the nose and / or cheeks. The conformity of the lens to other structures may include inflection points, such as the transition from a concave portion to a convex portion along the lens surface (e.g., surfaces 508 and / or 510 of FIG. 5, surfaces 612 and / or 614 of FIG. 6). The phrase "lens surface" refers to a surface that extends from one part of the perimeter of the lens to another part of the perimeter of the lens. The term "inflection" may be used herein with respect to a smoothly varying surface (without abrupt changes or discontinuities on the surface). Examples of abruptly changing surfaces can be cuts or holes that can produce a surface with a sharp 90-degree turn (e.g., a keyhole) in the thickness of the lens body. Another example of an abruptly changing surface can be a non-chamfered protrusion (a hook that engages with the frame) of the lens.

[0046] FIG. 14 is a cross-sectional view of a structure 1400 having a curved surface according to an exemplary embodiment. In some embodiments, the curved surface of the structure 1400 has a surface normal 1402 (90 degrees with respect to the surface), and its orientation depends on the curvature of the surface. The inflection point 1404 indicates where the curved surface switches from a convex portion to a concave portion and vice versa. Some of the surface normals 1402 are shown as diverging, which indicates a convex surface. Some of the surface normals are shown as converging, which indicates a concave surface. A lens having a two-dimensional surface may include a plurality of inflection points. Thus, in some embodiments, the inflection region may include a distribution of inflection points that are dispersed over a region on a line or on the lens surface (e.g., on surfaces 612 and / or 614 of FIG. 6).

[0047] In some embodiments, the bending region can occur in any part of the lens (e.g., the central part, the lateral part, and / or the transition part). That is, the bending region can occur in a surface region having a full vector front solution and / or an off-axis solution. Designing a bending region in a part having a full vector front solution may involve actual angular optical calculations for making the corresponding second surface (e.g., the second surface is designed based on the initial surface or another calculated surface). The second surface can be designed to provide the same optical effect to a typical wearer as would occur if there were no bending region. In some embodiments, the optical calculation of the bending region is such that, particularly when the bending region is in a part of the lens that will have a full vector front solution, and when the wearer's line of sight is in a direction slightly away from the front (e.g., 5° off-axis) of the lens, it can intentionally cause the same off-axis distortion aberration that a typical wearer would recognize if there were no bending zone. In other words, the actual optical behavior of this bending region is such that it is as if there were no bending region. Stated another way, even if all of the prism distortion aberration in the bending region could be drastically reduced in the calculation, the lens can still retain some intentional distortion aberration. That is, the calculation in the bending region can be performed to match the prism refractive power in the bending region to the prism refractive power just outside (i.e., adjacent to) the bending region (e.g., there is no abrupt change in the prism refractive power), so that even if distortion aberration remains, it substantially matches what would be recognized in a lens without a bending region.

[0048] An abrupt change in the prism refractive power may be more easily recognizable by the wearer of the lens. The advantage of minimizing an abrupt change in the prism refractive power is that the wearer does not recognize a sudden discontinuity in the distortion aberration when shifting their line of sight from one region of the lens to another.

[0049] In some embodiments, the inflection region can occur in the lateral portion of the lens. Designing the inflection region in a region having an off-axis solution can involve actual angle calculations for creating the corresponding aspheric surface. The aspheric surface can be designed to continue the off-axis solution across and beyond the inflection area. In some embodiments, rather than maintaining the prism distortion aberration as described above for the full vector forward scenario, the inflection region having an off-axis solution continues to minimize the prism distortion aberration. The reason for this is that the inflection region having an off-axis solution nominally does not include the distortion aberration up to, across, or beyond the inflection region.

[0050] In some embodiments, the inflection region can occur in the transition portion of the lens. Designing the inflection region in a portion having both full vector forward and off-axis solutions can involve actual angle calculations for creating the corresponding aspheric surface. The inflection region can include a gradient between maintaining the prism distortion aberration and minimizing the prism distortion aberration corresponding to the solution gradient between the central portion and the lateral portion.

[0051] In some embodiments, the inflection region is, for example, in an area of the lens where the light ray incident angle is large and total reflection occurs (e.g., a steeply shaped surface that conforms to the side of a typical wearer's nose), and does not have to conform to either the full vector forward or off-axis solution. Nevertheless, according to the above-described method steps, all or part of the inflection region can provide the intended optical effect to the user of the lens to an extent that could not be achieved with a conventional lens design otherwise.

[0052] Embodiments of the present disclosure provide a method of designing a lens by using an initial front point mesh as a basis for freeform back surface generation. However, those skilled in the art will understand that variations of this method are also possible, such as using an initial back point mesh as a basis for freeform front surface generation. It should be understood that a particular solution in the priority order may be given a higher or lower priority or may be omitted. The embodiments described herein are illustrative and not limiting.

[0053] Those skilled in the art will understand that lens design can be realized by many manufacturing methods known in the art. For example, a lens of high optical quality can be cut out from a preformed injection-molded lens blank. Alternatively, the lens can be directly molded into its final shape and size, eliminating the need for a post-molding cutting step. The lens or the lens blank from which the lens is cut can be injection-molded and can include a relatively hard and optically acceptable material, such as polycarbonate. Any material suitable for use as a lens can be used, which can be, for example, a polymer, polycarbonate (i.e., PC), allyl diglycol carbonate monomer (sold under the brand name CR-39®), glass (e.g., crown glass, flint glass), nylon, polyurethane, polyethylene, polyimide, polyethylene terephthalate (i.e., PET), biaxially oriented polyethylene terephthalate polyester film (i.e., BoPET, and one such polyester film is sold under the brand name MYLAR®), acrylic resin (e.g., polymethyl methacrylate, i.e., PMMA), urethane prepolymer, and high refractive index hybrid (e.g., Trivex®, Tribrid™), high refractive index plastic, transparent high refractive index monomer, transparent high refractive index polymer, polymer material, copolymer, doped material, any other suitable material, or any combination of materials. The surface shape of the lens can be produced in the lens blank molding and polishing process, and the lens shape can be cut out from the blank. The manufacturing methods described above are illustrative and not limiting.

[0054] Exemplary Lenses for Eyewear Lenses used in eyewear are typically required to meet market demands or safety standards set by regulatory bodies, such as sports organizations. The following description is mainly made with respect to non-corrective eyewear, but those skilled in the art will understand that similar techniques can also be used to improve corrective eyewear. Typically, material and thickness are two correlated safety parameters for eyewear lenses. For example, in the case of a highly shatterproof material, a thinner lens shape may be possible compared to other materials with lower shatter resistance. The refractive behavior of an eyewear lens is affected by the choice of material and thickness, and they thus affect, in particular, the magnitude of prism distortion aberration in off-axis viewing directions (e.g., lateral viewing directions and other viewing directions other than straight ahead). In the straight-ahead viewing direction of an eyewear lens, there is typically little to no prism distortion aberration over a wide range of materials and thicknesses, which is because many conventional lenses are developed for straight-ahead viewing, and thus light rays entering from the straight-ahead viewing direction will emerge in substantially the same direction and position as the light rays would be without the lens after passing through the lens. However, for light rays incident on the off-axis viewing area of the lens towards the wearer's eye, the angle of incidence is larger, and thereby the light is refracted and substantially deviates from the path corresponding to the case without the lens. Designing a thinner lens can be a solution to this problem, but the ability to design a thin lens to reduce prism refractive power can be limited by safety standards. Furthermore, a thinner lens becomes more flexible, and the optical advantages can be impaired when the lens bends. The present disclosure provides an eyewear lens that can maintain a thickness conforming to various legal safety standards while reducing the prism refractive power in off-axis viewing directions.

[0055] FIG. 5 is a schematic view of a lens 500 used in dual-lens eyewear according to an exemplary embodiment. In one embodiment, the lens 500 includes a lens body 502 and is configured to be positioned within the path of a forward line of sight that forms the central axis 504 of a typical wearer's monocular eye 506. The lens body 500 may be designed to be produced from lens materials commonly used in the art, and the lens materials are selected based on the intended application for their optical and mechanical properties such as low / high refractive index (e.g., 1.4 - 1.8), dispersion properties, UV attenuation, and impact resistance properties. Examples of materials may include polycarbonate, CR-39, Trivex, Tribrid, glass, and PMMA. In one embodiment, the lens body 502 includes a front surface 508 and a rear surface 510. In one embodiment, the lens thickness 514 is defined between the front surface 508 and the rear surface 510. In one embodiment, the lens thickness 514 at any point on the lens body is 4 mm or less and 1 mm or more. In one embodiment, the lens thickness 514 at any point on the lens body is 4 mm or less and 2 mm or more. In one embodiment, the lens thickness 514 at any point on the lens body is 3.5 mm or less and 2 mm or more. In one embodiment, the lens thickness 514 at any point on the lens body is 3.5 mm or less and 2.5 mm or more. In one embodiment, the lens thickness 514 at any point on the lens body is 3 mm or less and 2 mm or more. In one embodiment, the lens thickness 514 at any point on the lens body is 2 mm or less and 1 mm or more. In one embodiment, the lens thickness 514 at any point on the lens body is 1.7 mm or less and 1.2 mm or more. Those skilled in the art will appreciate that other minimum and maximum thicknesses of the lens thickness 514 may also be used.

[0056] In certain embodiments, the visual axis 512 extends from the eye 506 and the central axis 504 at an angle 516 away from the nose of a typical wearer, measured (e.g., following) along the horizontal meridian 515 of the rear surface 510 (see FIG. 12). In certain embodiments, each point along the horizontal meridian is associated with the angle of the visual axis 512 at the position where the visual axis 512 intersects each point along the horizontal meridian 515.

[0057] In certain embodiments, the front surface 508 has a ground surface (e.g., spherical, toric or cylindrical shape), and the rear surface 510 has a freeform shape. In certain embodiments, the front surface 508 has a freeform shape and the rear surface 510 has a ground surface. In certain embodiments, both the front surface 508 and the rear surface 510 have freeform shapes. Since eyewear lenses can have many different base curves, the embodiments described herein accommodate different base curves of the lens. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 4 curves or more. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 6 curves or more. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 8 curves or more. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 8.75 curves or more. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 10 curves or more. Those skilled in the art will appreciate that the embodiments of the present invention can be applied to lenses having any non-zero base curve in the horizontal and / or vertical directions. Those skilled in the art will further appreciate that for a ground surface having a certain base curve, the base curve of the lens blank may not be on an exact horizontal or vertical line when attached to eyewear or headgear. Although a freeform surface does not have a clearly defined single value of base curve, it has an average surface curvature comparable to that of a particular ground surface and can provide wrap-around characteristics similar to those of a ground surface.

[0058] As described above, the lens 500 can be designed to have turned surfaces as the front surface 508 and the rear surface 510. Without the correction provided by the embodiments of the present disclosure, due to the prism refractive power of the lens 500, a light ray 518 incident from a direction along the visual axis 512 can deviate from the visual axis 512 after passing through the lens 500, which can cause prism distortion aberration (e.g., an apparent shift in the position of a distant object). FIG. 5 shows different amounts of deviation of the light ray 518, which is indicated by the amount of angle 519 and depends on lens parameters such as the lens thickness 514 or the lens material and other parameters. For example, one amount of deviation is indicated by the light ray 518a and the corresponding angle 519a, and a further amount of deviation is indicated by the light ray 518b and the corresponding angle 519b. However, the embodiments described herein have a freeform shape on the front surface 508 and / or the rear surface 510 such that the prism refractive power of the lens 500 is reduced (e.g., the amount of deviation of the light ray 518 is reduced). In Tables 1 to 9, it is shown that a lower prism refractive power can be achieved with lenses utilizing the embodiments of the present disclosure than with conventional lenses.

[0059] In some embodiments, the prism refractive power of lens 500 using a freeform shape on front surface 508 and / or rear surface 510 is less than about 0.25 diopters across the entire points along horizontal meridian 515 associated with an angle of visual axis 512 of about 30 degrees or less. In some embodiments, the prism refractive power of lens 500 using a freeform shape on front surface 508 and / or rear surface 510 is less than about 0.35 diopters across the entire points along horizontal meridian 515 associated with an angle of visual axis 512 of about 40 degrees or less. In some embodiments, the prism refractive power of lens 500 using a freeform shape on front surface 508 and / or rear surface 510 is less than about 0.6 diopters across the entire points along horizontal meridian 515 associated with an angle of visual axis 512 of about 55 degrees or less. In some embodiments, the prism refractive power of lens 500 using a freeform shape on front surface 508 and / or rear surface 510 is less than about 0.8 diopters across the entire points along horizontal meridian 515 associated with an angle of visual axis 512 of about 80 degrees or less.

[0060] In one embodiment, the prism refractive power of lens 500 using a freeform shape on front face 508 and / or rear face 510 increases at an average rate of no more than about 0.01 diopter per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 of about 30 degrees or less. In one embodiment, the prism refractive power of lens 500 using a freeform shape on front face 508 and / or rear face 510 increases at an average rate of no more than about 0.01 diopter per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 from about 30 degrees to about 40 degrees. In one embodiment, the prism refractive power of lens 500 using a freeform shape on front face 508 and / or rear face 510 increases at an average rate of no more than about 0.01 diopter per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 from about 40 degrees to about 55 degrees. In one embodiment, the prism refractive power of lens 500 using a freeform shape on front face 508 and / or rear face 510 increases at an average rate of no more than about 0.01 diopter per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 from about 55 degrees to about 80 degrees.

[0061] In one embodiment, the prism refractive power P of lens 500 using a freeform shape on front face 508 and / or rear face 510 is related through all points along the horizontal meridian 515, to an angle θ of the visual axis 512 from about 30 degrees to about 55 degrees, by the relationship

Number

Number

[0062] As demonstrated by the data shown in Tables 1 - 9 and Figures 7 - 10, embodiments of the present disclosure can further improve the optical performance of the lens 500. Thus, in one embodiment, the prism refractive power of the lens 500 using a freeform shape on the front surface 508 and / or the rear surface 510 increases at an average rate of about 0.009 or less per degree of the increasing angle of the visual axis 512. In one embodiment, the prism refractive power of the lens 500 using a freeform shape on the front surface 508 and / or the rear surface 510 increases at an average rate of about 0.008 or less per degree of the increasing angle of the visual axis 512.

[0063] As suggested in the above embodiments, by designing the lens using the calculated freeform surface, the prism refractive power of the lens can be made to increase at a lower rate per degree of the increasing angle of the visual axis with respect to the forward direct line of sight. As a result, in one embodiment, the difference between the maximum and minimum prism refractive powers of the lens can be smaller compared to a conventional lens (the conventional lens differs in that it does not have a calculated freeform surface) having substantially the same parameters throughout a certain viewing angle range.

[0064] Referring back to Tables 1 - 9, for example, when considering only the horizontal line of sight range from 0 to 30 degrees, the conventional lens 1 has been shown to have a minimum prism refractive power of 0.04 diopters (horizontal 0 degrees) and a maximum prism refractive power of 0.25 diopters (horizontal 30 degrees). In other words, the prism refractive power of the conventional lens 1 varies by only 0.21 diopters (i.e., from 0.25 to 0.04) in the horizontal line of sight range of 0 to 30 degrees. However, the redesigned conventional lens 1 (having a calculated freeform surface) has been shown to have a minimum prism refractive power of 0.02 diopters (horizontal 0 degrees) and a maximum prism refractive power of 0.14 diopters (horizontal 30 degrees) when considering only the horizontal line of sight range from 0 to 30 degrees. In other words, the prism refractive power of the redesigned conventional lens varies by only 0.12 diopters in the horizontal line of sight range of 0 to 30 degrees. Therefore, the redesigned conventional lens 1 shows a significant improvement compared to its non - freeform version. Embodiments of the present disclosure can slow down the overall increase in prism refractive power within a certain viewing angle range.

[0065] In certain embodiments, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape on the front surface 508 and / or the rear surface 510 is about 0.20, 0.19, 0.15, 0.12, 0.08, or 0.04 diopters or less throughout the range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 30 degrees or less. In certain embodiments, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape on the front surface 508 and / or the rear surface 510 is about 0.32, 0.31, 0.25, 0.20, 0.15, or 0.10 diopters or less throughout the range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 40 degrees or less. In certain embodiments, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape on the front surface 508 and / or the rear surface 510 is about 0.56, 0.55, 0.45, 0.35, 0.25, 0.15, or 0.05 diopters or less throughout the range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 55 degrees or less.

[0066] Above, the prism power of the lens 500 was generally discussed for all base curves. However, Tables 1-9 and FIGS. 7-10 show that the optical performance of lenses without a calculated freeform surface degrades as the value of the base curve increases. For example, the prism power of a conventional 6-base curve lens is inferior (higher value) to that of a conventional 4-base curve lens. Thus, utilizing embodiments of the present disclosure, the prism power of a lens having a particular base curve can be lower than that generally discussed for all base curves.

[0067] Example of 6 curves: In certain embodiments, the prism power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more on the front surface 508 and / or the rear surface 510 is about 0.44 diopters or less through all points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 30 degrees or less. In certain embodiments, the prism power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more on the front surface 508 and / or the rear surface 510 is about 0.64 diopters or less through all points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 40 degrees or less. In certain embodiments, the prism power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more on the front surface 508 and / or the rear surface 510 is about 0.89 diopters or less through all points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 50 degrees or less. In certain embodiments, the prism power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more on the front surface 508 and / or the rear surface 510 is about 1.33 diopters or less through all points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 80 degrees or less.

[0068] In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more increases at an average rate of about 0.018 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 of about 30 degrees or less. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more increases at an average rate of about 0.018 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 of from about 30 degrees to about 40 degrees. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more increases at an average rate of about 0.018 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 of from about 40 degrees to about 50 degrees. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more increases at an average rate of about 0.018 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, associated with an angle of the visual axis 512 of from about 50 degrees to about 80 degrees.

[0069] In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more P is related, through all points along the horizontal meridian 515, to the angle θ of the visual axis 512 of from about 30 degrees to about 50 degrees, by the relationship

Equation

Number

[0070] As demonstrated by the data shown in Tables 1-9 and Figures 7-10, embodiments of the present disclosure can further improve the optical performance of the lens 500. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more increases at an average rate of about 0.016 diopters or less per degree of the increasing angle of the visual axis 512. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more increases at an average rate of about 0.014 diopters or less per degree of the increasing angle of the visual axis 512.

[0071] In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more is about 0.44, 0.36, 0.28, 0.20, 0.12, or 0.04 diopters or less throughout the range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 30 degrees or less. In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more is about 0.64, 0.54, 0.44, 0.34, 0.24, 0.14, or 0.04 diopters or less throughout the range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 40 degrees or less. In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more is about 0.89, 0.70, 0.55, 0.40, 0.25, or 0.10 diopters or less throughout the range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 50 degrees or less. For example, as shown in Table 4, the difference between the maximum and minimum prism refractive powers of a lens according to an exemplary embodiment having a toric 4×6 shape and a certain freeform shape rear surface is about 0.19 or less throughout the range of points associated with angles from 0 to 20 degrees.

[0072] In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more is about 0.35, 0.28, 0.20, 0.12, or is 0.04 diopters or less. In certain embodiments, on front surface 508 and / or rear surface 510, the difference between the maximum and minimum prism refractive powers of lens 500 using a freeform shape having a horizontal base curve of about 6 curves or more is about 0.43, 0.36, 0.28, 0.20, 0.12, or 0.04 diopters or less throughout the range of points along horizontal meridian 515 associated with an angle of the visual axis 512 of about 30 degrees to about 50 degrees.

[0073] Embodiments that use both freeform surfaces and turned surfaces with other viewing angle ranges and prism refractive power performance are within the scope of the present disclosure. As a non-limiting example, in certain embodiments, the difference between the maximum and minimum prism refractive powers of lens 500 where front surface 508 has a toric or freeform shape and rear surface 510 has the other of a toric and freeform shape is about 0.44, 0.40, 0.36, 0.32, 0.28, 0.24, 0.20, 0.16, 0.12, 0.08, or 0.04 diopters or less throughout the range of points along horizontal meridian 515 associated with an angle of visual axis 512 of about 30 degrees or less. In certain embodiments, the difference between the maximum and minimum prism refractive powers of lens 500 where front surface 508 has a toric or freeform shape and rear surface 510 has the other of a toric and freeform shape is about 0.35, 0.32, 0.29, 0.26, 0.23, 0.20, 0.17, 0.14, 0.11, 0.08, 0.05, or 0.02 diopters or less throughout the range of points along horizontal meridian 515 associated with an angle of visual axis 512 of about 20 degrees to about 40 degrees.

[0074] 8.75 Curve Example: As a further example of embodiments that can be considered with respect to Tables 1-9 and FIGS. 7-10, non-limiting specific examples of lenses are provided with respect to the graphs of Tables 6-8 and FIG. 9. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more is about 0.62 diopters or less throughout the points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 30 degrees or less. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more is about 0.82 diopters or less throughout the points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 40 degrees or less. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more is about 1.0 diopters or less throughout the points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 50 degrees or less. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more is about 1.56 diopters or less throughout the points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 80 degrees or less. For example, as shown in Table 8, the difference between the maximum and minimum prism refractive powers of a lens according to an exemplary embodiment having a horizontal base curve of 8.75 curves and a certain freeform rear surface is about 0.08 or less throughout the range of points associated with angles from 0 to 25 degrees (this difference is obtained by subtracting the prism refractive power of 0.04 at an angle of 0 degrees from the prism refractive power of 0.12 at an angle of 25 degrees).

[0075] In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curve or more is about 0.56, 0.44, 0.36, 0.28, 0.20, 0.12, or 0.04 diopters or less throughout the range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 30 degrees or less. In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curve or more is about 0.78, 0.68, 0.54, 0.44, 0.34, 0.24, 0.14, or 0.04 diopters or less throughout the entire range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 40 degrees or less. In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curve or more is about 0.94, 0.80, 0.75, 0.60, 0.45, 0.30, 0.18, or 0.05 diopters or less throughout the entire range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 50 degrees or less. In another non-limiting specific embodiment of the lens based on the graphs of Tables 6-8 and FIG. 10, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curve or more is 0.39, 0.37, 0.35, 0.33, 0.31, 0.29, 0.27, 0.25, 0.23, 0.21, 0.19, 0.17, 0.15, 0.13, 0.11, 0.09, 0.07, 0.05, 0.03, or 0.01 diopters or less throughout the entire range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 20 degrees to about 40 degrees. Throughout the entire range, it is about 0.78, 0.68, 0.54, 0.44, 0.34, 0.24, 0.14, or 0.04 diopters or less. In one embodiment, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curve or more is about 0.94, 0.80, 0.75, 0.60, 0.45, 0.30, 0.18, or 0.05 diopters or less throughout the entire range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 50 degrees or less. In another non-limiting specific embodiment of the lens based on the graphs of Tables 6-8 and FIG. 10, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curve or more is 0.39, 0.37, 0.35, 0.33, 0.31, 0.29, 0.27, 0.25, 0.23, 0.21, 0.19, 0.17, 0.15, 0.13, 0.11, 0.09, 0.07, 0.05, 0.03, or 0.01 diopters or less throughout the entire range of points along the horizontal meridian 515 associated with an angle of the visual axis 512 of about 20 degrees to about 40 degrees.

[0076] In one embodiment, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.019 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, which is associated with an angle of the visual axis 512 of about 30 degrees or less. In one embodiment, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.019 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, which is associated with an angle of the visual axis 512 of about 30 degrees to about 40 degrees. In one embodiment, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.019 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, which is associated with an angle of the visual axis 512 of about 40 degrees to about 50 degrees. In one embodiment, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.019 diopters or less per degree of increasing angle of the visual axis 512, through all points along the horizontal meridian 515, which is associated with an angle of the visual axis 512 of about 50 degrees to about 80 degrees.

[0077] In one embodiment, on the front surface 508 and / or the rear surface 510, the prism refractive power P of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more is related, through all points along the horizontal meridian 515, to an angle θ of the visual axis 512 of about 30 degrees to about 50 degrees, by the relationship

Equation

[0078] As demonstrated by the data shown in Tables 1-9 and Figures 7-10, embodiments of the present disclosure can further improve the optical performance of the lens 500. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.015 diopters or less per degree of increasing angle of the visual axis 512. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.011 diopters or less per degree of increasing angle of the visual axis 512. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.008 diopters or less per degree of increasing angle of the visual axis 512. In certain embodiments, on the front surface 508 and / or the rear surface 510, the prism refractive power of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more increases at an average rate of about 0.004 diopters or less per degree of increasing angle of the visual axis 512.

[0079] FIG. 6 is a schematic view of a single lens 600 for use in non-corrective eyewear according to an exemplary embodiment. In one embodiment, the single lens 600 includes a lens body 602 and is configured to be positioned within the paths of a left central axis 604 corresponding to the forward line of sight of a typical wearer's left eye 606 and a right central axis 608 corresponding to the forward line of sight of a typical wearer's right eye. Considerations regarding the material of the lens body 602 are the same as those described above for the lens body 502 (FIG. 5). In one embodiment, the lens body 602 includes a front surface 612 and a rear surface 614. In one embodiment, a lens thickness 616 is defined between the front surface 612 and the rear surface 614. In one embodiment, the lens thickness 616 is 2 mm or less and 1 mm or more at any point on the lens body 602. In one embodiment, the lens thickness 616 is 1.7 mm or less and 1.2 mm or more. One of ordinary skill in the art will appreciate that other minimum and maximum thicknesses of the lens thickness 616 may also be used.

[0080] In one embodiment, a left visual axis 618 extends at an angle 620 away from the nose of a typical wearer, measured (e.g., following) along a horizontal meridian 615 (FIG. 13) of the rear surface 614 from the left eye 606 and the left central axis 604. In one embodiment, each point of a set of points 617 (FIG. 13) along the horizontal meridian 615 is associated with the angle of the left visual axis 618 at the position where the left visual axis 618 intersects each point of the set of points 617.

[0081] In certain embodiments, the front surface 612 has a turned surface (e.g., spherical, toric or cylindrical shape), and the back surface 614 has a freeform shape. In certain embodiments, the front surface 612 has a freeform shape, and the back surface 614 has a turned surface. In certain embodiments, both the front surface 612 and the back surface 614 have freeform shapes. Since the eyewear lens can have a number of different base curves, the embodiments described herein are applicable to different base curves of the lens. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 4 curves or more. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 6 curves or more. In certain embodiments, the spherical, toric or cylindrical shape The surface having can have a horizontal base curve of about 8 curves or more. In certain embodiments, a surface having a spherical, toric or cylindrical shape can have a horizontal base curve of about 10 curves or more. It should be understood that the freeform surface does not have a single value of base curve, but has an average surface curvature comparable to a particular turned surface and can provide wrap-around characteristics similar to the turned surface.

[0082] In one embodiment, the single lens 600 is configured to fit within a frame and be secured to the frame for supporting the lens on the wearer's head. In one embodiment, the frame includes an eyeglass frame. The frame may include ear supports that are attached directly to the lens or ear supports that are attached to a face frame that supports the single lens 600 (or lens 500 of FIG. 5), such as rimless or rimmed glasses, respectively. In one embodiment, the frame includes protective headgear 1104 (FIG. 11), such as a sports helmet, a motorcycle helmet, a construction site safety helmet, etc. In one embodiment, the frame includes goggles, such as snow / ski goggles, motorcycle goggles, etc. In such an embodiment, the goggles may include a strap for supporting the goggles together with the lens on the wearer's head. In one embodiment, the single lens 600 is configured to fit within and be secured to an additional structure 1102, and the additional structure 1102 is configured to be attached to the protective headgear 1104. The single lens 600 may also be designed to fit other structures, such as facial features, such as the nose and / or cheeks. The fitting of the single lens 600 to other structures may include inflection points, such as transitions from concave to convex regions. For the purposes of the present disclosure, the inflection region of the single lens 600 may be an inflection curve (i.e., a series of inflection points along a line) rather than an inflection point.

[0083] In one embodiment, the single lens 600 conforms to the contours of the user's face, such as the user's nose or cheeks. In one embodiment, the single lens 600 includes contours for inertial moment management (e.g., features for increasing or decreasing the stiffness of the lens), aerodynamic management (e.g., features for increasing, decreasing, or redirecting airflow for drag or anti-fogging issues), and / or aesthetic purposes. With respect to fitting and contours, the single lens 600 may include regions on the front face 612 and the rear face 614 that have an inflection region, such as an area where the lens transitions generally from a convex shape to a generally concave shape or vice versa.

[0084] As described above, the single lens 600 can be designed to have turned surfaces as the front surface 612 and the rear surface 614. Without the correction according to the embodiments of the present disclosure, due to the prism refractive power of the single lens 600, the light ray 622 incident from the direction along the left visual axis 618 may deviate from the left visual axis 618 after passing through the single lens 600, which may cause prism distortion aberration (e.g., an apparent shift in the position of a distant object). A similar deviation may also occur for the light ray 623 incident from the direction along the right visual axis 624 and passing through the single lens 600. FIG. 6 shows different amounts of deviation of the light ray 622, which is indicated by the amount of angle 625 and depends on lens parameters such as the lens thickness 616 or the lens material among other parameters. For example, one amount of deviation is indicated by the light ray 622a and the corresponding angle 625a, and a further amount of deviation is indicated by the light ray 622b and the corresponding angle 625b. Similarly for the light ray 627, an exemplary amount of deviation is indicated by the light ray 623a and the corresponding angle 627a, and another exemplary amount of deviation is indicated by the light ray 623b and the corresponding angle 627a. However, the embodiments described herein use a freeform shape on the front surface 612 and / or the rear surface 614 to reduce the prism refractive power of the single lens 600. Tables 1 to 9 and FIGS. 7 to 10 show that lenses utilizing the embodiments of the present disclosure can achieve a lower prism refractive power than conventional lenses.

[0085] In one embodiment, a freeform shape is used on the front surface 612 and / or the rear surface 614 The prism refractive power of the single lens 600 present is below about 0.25 diopters through all of the points of the point set 617, associated with an angle of the left visual axis 618 of about 30 degrees or less. In certain embodiments, the prism refractive power of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 is below about 0.35 diopters through all of the points of the point set 617, associated with an angle of the left visual axis 618 of about 40 degrees or less. In certain embodiments, the prism refractive power of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 is below about 0.6 diopters through all of the points of the point set 617, associated with an angle of the left visual axis 618 of about 55 degrees or less. In certain embodiments, the prism refractive power of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 is below about 0.8 diopters through all of the points of the point set 617, associated with an angle of the left visual axis 618 of about 80 degrees or less.

[0086] In certain embodiments, the prism refractive power of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 increases at an average rate of about 0.01 diopter or less per degree of increasing angle of the left visual axis 618, through all of the points of the point set 617, associated with an angle of the left visual axis 618 of about 30 degrees or less. In certain embodiments, the prism refractive power of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 increases at an average rate of about 0.01 diopter or less per degree of increasing angle of the left visual axis 618, through all of the points of the point set 617, associated with an angle of the left visual axis 618 from about 30 degrees to about 40 degrees. In certain embodiments, the prism refractive power of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 increases at an average rate of about 0.01 diopter or less per degree of increasing angle of the left visual axis 618, through all of the points of the point set 617, associated with an angle of the left visual axis 618 from about 40 degrees to about 55 degrees. In certain embodiments, the prism refractive power of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 increases at an average rate of about 0.01 diopter or less per degree of increasing angle of the left visual axis 618, through all of the points of the point set 617, associated with an angle of the left visual axis 618 of about 80 degrees or less.

[0087] In certain embodiments, the prism refractive power P of the single lens 600 using a freeform shape on the front surface 612 and / or the rear surface 614 is related to the angle θ of the left visual axis 618 from about 30 degrees to about 55 degrees, through all of the points of the point set 617, by the relationship

Number

Number

[0088] In one embodiment, the right visual axis 624 extends at another angle 626 away from the nose of a typical wearer that is measured (e.g., follows) along the horizontal meridian 615 (FIG. 13) from the left eye 610 and the right central axis 608. In one embodiment, each point of the set of points 619 (FIG. 13) along the horizontal meridian 615 is associated with the angle of the right visual axis 620 at the position where the right visual axis 620 intersects each point of the set of points 619. Considerations for prism refractive power with respect to the right eye 610 and the right visual axis 608 are similar and it should be understood that they can be reversed with respect to the prism refractive power described above in the embodiment with respect to the left visual axis 604. It should be understood that considerations for prism refractive power with respect to the right eye 610 and the right visual axis 608 are similar and can be reversed with respect to the prism refractive power described above in the embodiment with respect to the left visual axis 604.

[0089] Furthermore, Tables 1 - 9 and FIGS. 7 - 10 show that embodiments of the present disclosure can further improve the optical performance of the single lens 600, similar to the performance embodiments described above with respect to the lens 500 (FIG. 5), and that the prism refractive power of lenses with a particular base curve utilizing embodiments of the present disclosure can be lower than that generally discussed for all base curves. Thus, one of ordinary skill in the art will understand that the characteristics of prism refractive power described above in the embodiments of the lens 500 can be applied to the single lens 600 and vice versa.

[0090] In one embodiment, the single lens 600 includes a central portion 628 and a lateral portion 630. In one embodiment, the central portion 628 includes a binocular forward view solution (e.g., a full vector forward view). In one embodiment, the lateral portion 630 includes a monocular off-axis view solution. In one embodiment, a transition portion 632 connects the central portion 628 and the lateral portion 630. In one embodiment, the transition portion 632 provides a smooth and gradual transition between the binocular forward view solution of the central portion 628 and the monocular off-axis view solution of the lateral portion 630. In one embodiment, the transition portion 632 is defined between angles of the left viewing axis 618 of about 5 degrees to about 40 degrees. In one embodiment, the transition portion 632 is defined between angles of the left viewing axis 618 of about 10 degrees to about 30 degrees. In one embodiment, the transition portion 632 is defined between angles of the left viewing axis 618 of about 15 degrees to about 20 degrees. In one embodiment, the transition portion 632 is defined between angles of the left viewing axis 618 of about 5 degrees to about 15 degrees. In one embodiment, the transition portion 632 is defined between angles of the left viewing axis 618 of about 10 degrees to about 20 degrees. In one embodiment, the transition portion 632 is defined between angles of the left viewing axis 618 of about 15 degrees to about 25 degrees. In one embodiment, the transition portion 632 is defined between angles of the left viewing axis 618 of about 20 degrees to about 25 degrees. Those skilled in the art will understand that for the angle of the right viewing axis 624, another lateral portion and another transition portion can be defined by applying the same limitations as those described above for the transition portion 632.

[0091] FIG. 15 is a schematic diagram of a single lens 600, but in a different cross section than that shown in FIG. 6. The cross section shown in FIG. 15 sits lower on a typical wearer's face (including, for example, the nose contour). In some embodiments, the single lens 600 includes one or more inflection regions 634. The one or more inflection regions 634 are designed to create a contour in the single lens 600 that matches, for example, the facial features of a typical wearer (for example, the bridge of the nose, the cheeks, the eye sockets). Surface normals 636 are drawn to show the concavity of the surface. The surface normals 636 diverge for the convex portion of the surface 612 and converge for the concave portion of the surface 612. It should be understood that the convex / concave behavior can be relative to which side of the single lens 600 is being referred to. For example, the convex portion of the surface 612 can be the concave portion of the surface 614. 15 uses a single lens 600 as a reference, it should be understood that embodiments including an inflection point (e.g., inflection region 634) are contemplated for any eyewear lens (e.g., for lens 500 of FIG. 5). For example, the features relating to inflection region 634 of single lens 600 may be applied to lens 500 (FIG. 5) as well.

[0092] 6, in some embodiments, the inflection region of the single lens 600 can occur in any portion of the single lens 600 (e.g., the central portion 628, the side portions 630, and / or the transition portion 632). That is, the inflection region can occur in an area having a full vector forward looking solution and / or an off-axis looking solution.

[0093] In one embodiment, the single lens 600 includes an inflection region disposed in a central portion 628. The inflection region may be designed such that the prismatic distortion in the inflection region matches the prismatic distortion just outside (or adjacent to) the inflection region.

[0094] In one embodiment, the single lens 600 includes an inflection region disposed at the side portion 630. The inflection region may be designed such that prismatic distortion in the inflection region is minimized.

[0095] In some embodiments, the single lens 600 can be modified to implement a dual lens solution, for example, by splitting the single lens 600 in half (e.g., cutting or otherwise separating it) such that a left eye lens and a right eye lens are fabricated. Also, although some embodiment features are discussed directly in relation to single lens or dual lens eyewear, it should be understood that any of the features of all the embodiments described herein in relation to a single lens (e.g., single lens 600) are applicable to a lens for dual lens eyewear (e.g., lens 500 of FIG. 5) and vice versa.

[0096] Embodiments of the present disclosure relate to lenses used in non-corrective eyewear. However, those skilled in the art will understand that the peripheral vision correction provided by the embodiments of the present disclosure can also be applied to prescription lenses having intentional (e.g., by prescription) optical power and aberrations.

[0097] FIG. 7 is a graph plot comparing the overall prism diopters of the original conventional lens 1 (measurement) of Table 1 and the exemplary freeform redesigned conventional lens 1 (simulation) of Table 2. Values closer to 0 are more preferred. This simulation shows that when using the freeform redesign according to the embodiments of the present disclosure, the overall prism diopter generally decreases throughout the range of the horizontal visual axis angle of the conventional lens 1.

[0098] FIG. 8 is a graph plot comparing the overall prism diopters of the original conventional lens 2 (simulation) of Table 3 and the exemplary freeform redesigned conventional lens 2 (simulation) of Table 4. Values closer to 0 are more preferred. Similar to the comparison of the conventional lens 1, this simulation also shows that when using the freeform redesign according to the embodiments of the present disclosure, the overall prism diopter generally decreases throughout the range of the horizontal visual axis angle of the conventional lens 2.

[0099] FIG. 9 is a graph plot comparing the overall prism refractive power of the original conventional lens 4 (measurement) in Table 6, the original conventional lens 4 (simulation) in FIG. 7, and the freeform redesigned conventional lens 4 (simulation) in Table 8. The closer the value is to 0, the more preferable. This simulation shows that when using the freeform redesign according to the embodiments of the present disclosure, the overall prism refractive power generally decreases throughout the range of the horizontal visual axis angle of the conventional lens 4. The improvement in optical performance is more significant compared to the conventional lens 4, which shows a reduction in prism refractive power to about one-fifth compared to that regarding the conventional lens 1 or 2. In addition, here, the fidelity of the simulation algorithm is verified, and it is shown that the prism refractive powers obtained by simulation and measurement of the conventional lens 4 are in good agreement.

[0100] FIG. 10 is a graph plot comparing the overall prism refractive power of the exemplary freeform vision shield (measurement) in Table 9 and the original conventional lens 1 (measurement) in Table 1. The closer the value is to 0, the more preferable. This graph compares actual measurements, and this vision shield has a freeform redesign according to the embodiments of the present disclosure. The overall prism refractive power of the vision shield increases at a low rate of 0.13 to 0.25 diopters at 20 to 90 degrees and is below 0.25 diopters throughout the range of its horizontal visual axis angle. Below.

[0101] Regarding the metrics for evaluating prism distortion aberration, those skilled in the art will understand that the prism refractive power mentioned in the embodiments of the present disclosure can be explained in other equivalent aspects. For example, the features described in terms of prism refractive power can also be explained in terms of angular displacement or deviation, the apparent displacement of an object at a certain distance from the wearer, or other equivalent metrics, some of which are shown in Tables 1 to 9. The metrics used herein to evaluate prism distortion aberration are exemplary and not limiting.

[0102] One skilled in the art will recognize that the lens surface can include shapes having various base curves. For example, the measurements of the vision shield shown in Table 9 and FIG. 10 have variable base curves in the range of 3 to 10 between the ends of the lens. The forward viewing region that can be defined from about 25 degrees to the left to 25 degrees to the right (e.g., at the visual axis angle) has a base curve in the range of 5.5 to 10, and the 10 curve is located closer to the center.

[0103] It should be recognized that embodiments including prism refractive power performance can cover any viewing angle range, and the present disclosure includes all possible viewing angle ranges, but this does not provide an exhaustive list of all possible combinations. For example, on the front surface 508 and / or the rear surface 510, an embodiment is described with respect to FIG. 5 where the prism refractive power of the lens 500 having a horizontal base curve of about 6 or more is related to the angle of the visual axis 512 from about 30 degrees to about 40 degrees, increasing at an average rate of no more than about 0.018 diopters per degree of increasing angle of the visual axis 512 throughout the points along the horizontal meridian 515. Here, a horizontal viewing range of 30 to 40 degrees is given as an example. Embodiments regarding larger viewing angle ranges covering a narrower range of off-axis viewing angles closer to the forward line of sight (e.g., in the range of 20 to 40 degrees horizontally) or most of the off-axis viewing (e.g., 10 to 90 degrees horizontally) are also conceivable. In such embodiments, the prism refractive power performance for a certain angle range can be derived from the values in Tables 1 to 9.

[0104] As an example of different angular ranges, in the embodiments relating to the data of FIGS. 5 and 6, on the front surface 508 and / or the rear surface 510, the difference between the maximum and minimum prism refractive powers of the lens 500 using a freeform shape having a horizontal base curve of about 8.75 curves or more is about 0.40, 0.30, 0.20, 0.10 or 0.05 diopters or less throughout the range of points along the horizontal meridian 515, which is associated with the angle of the visual axis 512 of about 25 degrees to about 45 degrees. For this embodiment, Table 6 shows data for many horizontal viewing angles of a conventional lens having a base curve of about 8.75, for example, horizontally 25 to 45 degrees. The diopter difference between the maximum and minimum for this conventional lens and this viewing angle range is about 0.42 diopters. Thus, using the diopter improvement method disclosed herein, the redesigned 8.75 curve lens can have a diopter difference between the maximum and minimum values of less than 0.42 (e.g., 0.40) for the selected viewing angle range (in this case, about 25 to 45 degrees). Other embodiments derived in this way that cover other line of sight angle ranges and prism refractive power performance are also within the scope of the present disclosure. By using the diopter improvement method disclosed herein, the redesigned lens can have any diopter maximum value or diopter difference that is, for example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or more better than its corresponding conventional lens, as demonstrated by Tables 1-9, for a particular viewing angle range. In other words, while specific combinations of angular ranges and the difference between the diopter maximum value and the maximum-minimum value are disclosed herein, other combinations of viewing angle ranges and improvements in viewing angle and prism refractive power relative to conventional lenses, as demonstrated by and directly derivable from Tables 1-9, are also within the scope of the present disclosure.

[0105] Similarly, embodiments can relate to lens surfaces having a particular shape. The following exemplary embodiments relate to toric shapes, but similar embodiments having spherical or cylindrical shapes It should be recognized that various states are possible. With respect to FIG. 6, in one embodiment, the front surface 612 has one of a toric and a freeform shape, and the rear surface 614 has the other of a toric and a freeform shape. In one example of such an embodiment, the prism refractive power of the single lens 600 is 0.44 diopters or less across all points of the point set 617 associated with an angle of the left visual axis 618 of about 30 degrees or less. In another example of such an embodiment, the prism refractive power of the single lens 600 is 0.64 diopters or less across all points of the point set 617 associated with an angle of the left visual axis 618 of about 40 degrees or less. In yet another example of such an embodiment, the prism refractive power of the single lens 600 is 0.89 diopters or less across all points of the point set 617 associated with an angle of the left visual axis 618 of about 50 degrees or less. Also, as described above, embodiments that use both freeform surfaces and lathe-cut surfaces with other viewing angle ranges and prism refractive power performance are within the scope of the present disclosure.

[0106] Thus, various embodiments provide a method for providing a lens having at least one freeform surface (also referred to herein as a "true angle optical system") for different angles of incidence from the wearer's eye to the surface of the lens. By recognizing the novel relationships described herein between the wearer's line of sight and the unique configurations of the inner and outer surfaces of the lens, it is possible to use any of a variety of lens designs while minimizing prism distortion aberration according to the present disclosure. For example, a designer can select a desired orientation and curvature of the lens with respect to the wearer's line of sight. The orientation and curvature can be selected from the proximity to the wearer's eye surface, including parameters that achieve a wide range of tilts (i.e., the "tilt" of the lens in the vertical direction), horizontal tilts, base curve values, and high wrap-around. Thus, the freeform shape of the lens surface can be selected by the method of the present disclosure to minimize prism distortion aberration. This improvement has many advantages over conventional lenses. For example, it expands the range of lens designs for different styles, fits different interpupillary distances of the wearer with little degradation of optical performance, and enables the lens to be fitted into a wide range of frame / headgear designs.

[0107] Although the present disclosure described above describes measurements and corrections with respect to the horizontal visual axis, those skilled in the art will appreciate that similar techniques can be used for measurements and corrections with respect to the vertical visual axis or in directions or regions having both horizontal and vertical components.

[0108] Although embodiments of the present disclosure have been disclosed, those skilled in the art will understand that the present disclosure extends to other alternative embodiments and / or uses of the present invention, as well as obvious modifications and equivalents thereof, in addition to the specifically disclosed embodiments. Additionally, although some variations of the embodiments are illustrated and described in detail, other variations within the scope of the present disclosure will be readily apparent to those skilled in the art based on the present disclosure. Various combinations or partial combinations of the specific features and aspects of the embodiments can also be made, and it is contemplated that they will still be within the scope of the present invention. It should be understood that different aspects of the present invention disclosed can be formed by combining or replacing various features and aspects of the disclosed embodiments with each other. Therefore, at least a part of the scope of the present disclosure disclosed herein should not be limited by the specifically disclosed embodiments described above.

Claims

1. 1. A lens for use in combination with a frame for supporting said lens in a path of direct forward gaze forming a central axis of one eye of a typical wearer in non-corrective eyewear or headgear, comprising: A lens body, a front surface having a spherical, toric, cylindrical or freeform shape; A rear surface having a freeform shape. Lens body including Including, a lens thickness is defined between the anterior surface and the posterior surface; a visual axis extends from the eye and the central axis at an angle from the central axis away from the typical wearer's nose, measured along the posterior horizontal meridian; Each point along the horizontal meridian of the posterior surface is associated with an angle of the visual axis at which the visual axis intersects with each point along the horizontal meridian of the posterior surface; and A lens having a prismatic power of about 0.23 diopters or less throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees or less.

2. 10. The lens of claim 1, wherein the lens thickness at any point on the lens body is less than about 2 mm and greater than about 1 mm.

3. 10. The lens of claim 1, wherein the lens thickness at any point on the lens body is less than or equal to about 1.7 mm and greater than or equal to about 1.2 mm.

4. The lens of claim 1 , wherein the spherical, toric or cylindrical shape has a horizontal base curve of about 4 or more curves.

5. 10. The lens of claim 1, wherein the spherical, toric or cylindrical shape has a horizontal base curve of about 6 curves or more.

6. 10. The lens of claim 1, wherein the spherical, toric or cylindrical shape has a horizontal base curve of about 8 curves or more.

7. 10. The lens of claim 1, wherein the spherical, toric or cylindrical shape has a horizontal base curve of about 10 curves or more.

8. 10. The lens of claim 1, wherein the prismatic power of the lens is less than or equal to about 0.35 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 40 degrees.

9. 10. The lens of claim 1, wherein the prismatic power of the lens is less than or equal to about 0.6 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 55 degrees.

10. 10. The lens of claim 1, wherein the prismatic power of the lens is less than or equal to about 0.8 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 80 degrees.

11. The prismatic power of the lens is associated with angles of the visual axis of less than about 30 degrees.

10. The lens of claim 1, wherein the posterior surface increases at an average rate of about 0.01 diopters or less per degree of increasing angle of the visual axis throughout all points along the horizontal meridian of the posterior surface.

12. 10. The lens of claim 1, wherein the prismatic power of the lens increases at an average rate of about 0.01 diopters or less per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

13. 10. The lens of claim 1, wherein the prismatic power of the lens increases at an average rate of about 0.01 diopters or less per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 55 degrees.

14. 10. The lens of claim 1, wherein the prismatic power of the lens increases at an average rate of about 0.01 diopters or less per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 55 degrees and about 80 degrees.

15. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 30 degrees to about 55 degrees, through points along the horizontal meridian of the posterior surface, [0010] The lens of claim 1 ,

16. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 55 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, [0025] The lens of claim 1 ,

17. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 30 degrees to about 55 degrees, through points along the horizontal meridian of the posterior surface, [0030] The lens of claim 1 ,

18. The horizontal prism power P of the lens when worn in diopters is related to the visual axis angle θ in degrees from about 55 degrees to about 90 degrees. Throughout the points along the meridians, the relationship [0045] The lens of claim 1 ,

19. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 30 degrees to about 55 degrees, through points along the horizontal meridian of the posterior surface, [0050] The lens of claim 1 ,

20. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 55 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, [006] The lens of claim 1 ,

21. The lens of claim 1 , which is one of two lenses of dual lens eyewear.

22. the lens is a single lens, the visual axis is a first visual axis, the eye is a first eye, The single lens is configured to be supported in a forward line of sight path that forms a central axis of a second eye of the typical wearer; a second visual axis extends from the second eye and the central axis of the second eye at an angle from the central axis of the second eye measured along the horizontal meridian of the posterior surface away from the typical wearer's nose in a direction opposite to the direction of the first visual axis; each point of a second set of points along the horizontal meridian of the posterior surface is associated with an angle of the second visual axis at which the second visual axis intersects the respective point of the second set of points; and 2. The lens of claim 1, wherein the prismatic power of the lens is less than or equal to about 0.23 diopters throughout the second set of points associated with the second visual axis angle of less than or equal to about 30 degrees.

23. The lens of claim 1 , wherein the lens body is configured to conform to a shape of the frame and be secured to the frame.

24. Eyewear comprising the lens and frame of claim 1.

25. 25. The eyewear of claim 24, wherein the frame comprises a glasses or goggle frame.

26. Protective headgear comprising the lens of claim 1.

27. The lens body is configured to conform to the shape of and be secured to the additional structure; and 27. The protective headgear of claim 26, wherein the additional structure is configured to be secured to the protective headgear.

28. The lens of claim 1 , wherein the posterior surface further comprises an inflection region, and wherein the prismatic power in the inflection region is substantially similar to the prismatic power in a region adjacent the inflection region.

29. 1. A method of designing a lens for non-corrective eyewear or headgear, comprising: generating a point mesh of an initial front surface of the lens; generating a point mesh of a freeform posterior surface of the lens based on the initial front surface, the points of the point mesh of the freeform posterior surface corresponding to the points of the point mesh of the initial front surface; and generating the point mesh of the freeform back surface comprises: determining a forward visual axis for the lens based at least on a wear position of the lens relative to an eye of a typical wearer; identifying a seed point on the initial front surface, the seed point being a starting point for subsequent iterations; assigning an initial thickness at the seed point; calculating a surface normal of a first point on the freeform back surface that corresponds to the seed point; placing the first point on the freeform back surface according to the initial thickness and a refraction of a ray intersecting the seed point from the surface normal to the freeform back surface; calculating a surface normal at a point on the freeform back surface adjacent to the first point that corresponds to a point in the point mesh of the initial front surface adjacent to the seed point; calculating thicknesses of the points adjacent to the seed point using an optimization algorithm, the optimization algorithm including calculating refraction of light rays based on the calculated surface normals at the points adjacent to the first point on the freeform back surface; placing a point adjacent to the first point on the freeform back surface according to the calculated thickness of the point adjacent to the seed point; placing additional points on the freeform back surface by iteratively calculating surface normals and thicknesses of points adjacent to the placed points; A method comprising:

30. 30. The method of claim 29, wherein the optimization algorithm follows a priority order that includes first the most uniform optical path length solution, second the thinnest possible solution, and third the most uniform thickness solution.

31. 30. The method of claim 29, further comprising generating a freeform front surface of the lens by iterative calculation of surface normals and thickness based on a progressive reassignment of front surface reference points, wherein the freeform front surface replaces the initial front surface.

32. A lens for non-corrective eyewear or headgear, for one eye of a typical wearer.

1. A lens for use in combination with a frame for supporting said lens in a forward line of sight path that defines a central axis of said lens, A lens body, a front surface having a spherical, toric, cylindrical or freeform shape; A rear surface having a freeform shape. Lens body including Including, the spherical, toric, cylindrical or freeform shape of the front surface has a horizontal base curve of about 6 curves or more; a lens thickness is defined between the anterior surface and the posterior surface; a visual axis extends from the eye and the central axis at an angle from the central axis away from the typical wearer's nose, measured along the posterior horizontal meridian; Each point along the horizontal meridian of the posterior surface is associated with an angle of the visual axis at which the visual axis intersects with each point along the horizontal meridian of the posterior surface; and A lens having a prismatic power of about 0.44 diopters or less throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees or less.

33. 33. The lens of claim 32, wherein the lens thickness at any point on the lens body is less than about 2 mm and greater than about 1 mm.

34. 33. The lens of claim 32, wherein the lens thickness at any point on the lens body is less than or equal to about 1.7 mm and greater than or equal to about 1.2 mm.

35. 33. The lens of claim 32, wherein the spherical, toric or cylindrical shape has a horizontal base curve of about 8 curves or more.

36. 33. The lens of claim 32, wherein the anterior surface has a toric shape.

37. 33. The lens of claim 32, wherein the prismatic power of the lens is less than or equal to about 0.64 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 40 degrees.

38. 33. The lens of claim 32, wherein the prismatic power of the lens is less than or equal to about 0.89 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 50 degrees.

39. 33. The lens of claim 32, wherein the prismatic power of the lens is less than or equal to about 1.33 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 80 degrees.

40. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.018 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 30 degrees.

41. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.018 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

42. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.018 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

43. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.018 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

44. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.016 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 30.

45. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.016 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 to about 40 degrees.

46. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.016 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

47. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.016 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

48. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.014 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 30 degrees.

49. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.014 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

50. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.014 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

51. 33. The lens of claim 32, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.014 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

52. The horizontal prism power P of the lens when worn, in diopters, is related to the angle θ of the visual axis, in degrees, of about 30 degrees to about 50 degrees. Throughout the points along the meridians, the relationship [0070] 33. The lens of claim 32, wherein

53. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 50 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, [0080] 33. The lens of claim 32, wherein

54. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, of about 30 degrees to about 50 degrees, through points along the horizontal meridian of the posterior surface, [0090] 33. The lens of claim 32, wherein

55. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 50 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, [0089] 33. The lens of claim 32, wherein

56. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, of about 30 degrees to about 50 degrees, through points along the horizontal meridian of the posterior surface, ##EQU00011## 33. The lens of claim 32, wherein

57. The horizontal prism power P of the lens when worn in diopters is related to the angle θ of the visual axis in degrees from about 50 degrees to about 90 degrees. Throughout the points along the meridians, the relationship ##EQU00012## 33. The lens of claim 32, wherein

58. 33. The lens of claim 32, which is one of two lenses of dual lens eyewear.

59. the lens is a single lens, the visual axis is a first visual axis, the eye is a first eye, The single lens is configured to be supported in a forward line of sight path that forms a central axis of a second eye of the typical wearer; a second visual axis extends from the second eye and the central axis of the second eye at an angle from the central axis of the second eye measured along the horizontal meridian of the posterior surface away from the typical wearer's nose in a direction opposite to the direction of the first visual axis; each point of a second set of points along the horizontal meridian of the posterior surface is associated with an angle of the second visual axis at which the second visual axis intersects the respective point of the second set of points; and 33. The lens of claim 32, wherein the prismatic power of the lens is less than or equal to about 0.44 diopters throughout the second set of points associated with angles of the second visual axis less than or equal to about 30 degrees.

60. 33. The lens of claim 32, wherein the lens body is configured to conform to a shape of the frame and be secured to the frame.

61. Eyewear comprising the lens and frame of claim 32.

62. 62. The eyewear of claim 61 , wherein the frame comprises a glasses or goggle frame.

63. 33. Protective headgear comprising a lens according to claim 32.

64. The lens body is configured to conform to the shape of and be secured to the additional structure; and 63. The protective headgear of claim 62, wherein the additional structure is configured to be secured to the protective headgear.

65. 33. The lens of claim 32, wherein the posterior surface further comprises an inflection region, and wherein the prismatic power in the inflection region is substantially similar to the prismatic power in a region adjacent the inflection region.

66. 1. A lens for use in combination with a frame for supporting said lens in a path of direct forward gaze forming a central axis of one eye of a typical wearer in non-corrective eyewear or headgear, comprising: A lens body, a front surface having a spherical, toric, cylindrical or freeform shape; A rear surface having a freeform shape. Lens body including Including, the spherical, toric, cylindrical or freeform shape of the front surface has a horizontal base curve of about 8.75 curves or greater; a lens thickness is defined between the anterior surface and the posterior surface; a visual axis extends from the eye and the central axis at an angle from the central axis away from the typical wearer's nose, measured along the posterior horizontal meridian; Each point along the horizontal meridian of the posterior surface is associated with an angle of the visual axis at which the visual axis intersects with each point along the horizontal meridian of the posterior surface; and A lens having a prismatic power of about 0.62 diopters or less throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees or less.

67. 67. The lens of claim 66, wherein the lens thickness at any point on the lens body is less than about 2 mm and greater than about 1 mm.

68. 67. The lens of claim 66, wherein the lens thickness at any point on the lens body is less than about 1.7 mm and greater than about 1.2 mm.

69. 67. The lens of claim 66, wherein the prismatic power of the lens is less than or equal to about 0.82 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 40 degrees.

70. 67. The lens of claim 66, wherein the prismatic power of the lens is less than or equal to about 0.9 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 50 degrees.

71. 67. The lens of claim 66, wherein the prismatic power of the lens is less than or equal to about 1.56 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 80 degrees.

72. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.019 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 30 degrees.

73. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.019 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

74. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.019 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

75. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.019 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

76. The prismatic power of the lens is associated with angles of the visual axis of about 30 degrees or less, and increases with increasing angle of the visual axis through points along the horizontal meridian of the posterior surface.

67. The lens of claim 66, wherein the iris increases at an average rate of about 0.015 diopters or less.

77. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.015 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

78. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.015 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

79. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.015 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

80. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.011 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 30 degrees.

81. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.011 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

82. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.011 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

83. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.011 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

84. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.008 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 30 degrees.

85. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.008 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

86. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.008 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

87. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.008 diopters per degree of increasing angle of the visual axis through points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

88. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.004 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 30 degrees.

89. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.004 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 30 degrees and about 40 degrees.

90. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.004 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 40 degrees and about 50 degrees.

91. 67. The lens of claim 66, wherein the prismatic power of the lens increases at an average rate of less than or equal to about 0.004 diopters per degree of increasing angle of the visual axis throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis between about 50 degrees and about 80 degrees.

92. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, of about 30 degrees to about 50 degrees, through points along the horizontal meridian of the posterior surface, ##EQU00013## 67. The lens of claim 66, wherein

93. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 50 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, ##EQU14## 67. The lens of claim 66, wherein

94. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, of about 30 degrees to about 50 degrees, through points along the horizontal meridian of the posterior surface, ##EQU00015## 67. The lens of claim 66, wherein

95. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 50 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, ##EQU00016## 67. The lens of claim 66, wherein

96. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, of about 30 degrees to about 50 degrees, through points along the horizontal meridian of the posterior surface, ##EQU00017## 67. The lens of claim 66, wherein

97. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 50 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, [0018] 67. The lens of claim 66, wherein

98. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, of about 30 degrees to about 50 degrees, through points along the horizontal meridian of the posterior surface, [0019] 67. The lens of claim 66, wherein

99. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 50 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, [0020] 67. The lens of claim 66, wherein

100. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, of about 30 degrees to about 50 degrees, through points along the horizontal meridian of the posterior surface, ##EQU00021## 67. The lens of claim 66, wherein

101. The prismatic power P of the lens when worn, in diopters, is related to the visual axis angle θ, in degrees, from about 50 degrees to about 90 degrees, through points along the horizontal meridian of the posterior surface, [0022] 67. The lens of claim 66, wherein

102. 67. The lens of claim 66, which is one of two lenses of dual lens eyewear.

103. the lens is a single lens, the visual axis is a first visual axis, the eye is a first eye, The single lens is configured to be supported in a forward line of sight path that forms a central axis of a second eye of the typical wearer; a second visual axis extends from the second eye and the central axis of the second eye at an angle from the central axis of the second eye measured along the horizontal meridian of the posterior surface away from the typical wearer's nose in a direction opposite to the direction of the first visual axis; each point of a second set of points along the horizontal meridian of the posterior surface is associated with an angle of the second visual axis at which the second visual axis intersects the respective point of the second set of points; and 67. The lens of claim 66, wherein the prismatic power of the lens is less than or equal to about 0.62 diopters throughout the second set of points associated with angles of the second visual axis less than or equal to about 30 degrees.

104. 67. The lens of claim 66, wherein the lens body is configured to conform to a shape of the frame and be secured to the frame.

105. 67. Eyewear comprising the lens and frame of claim 66.

106. 106. The eyewear of claim 105, wherein the frame comprises a glasses or goggle frame.

107. 67. Protective headgear comprising a lens according to claim 66.

108. The lens body is configured to conform to the shape of and be secured to the additional structure; and 108. The protective headgear of claim 107, wherein the additional structure is configured to be secured to the protective headgear.

109. 67. The lens of claim 66, wherein the posterior surface further comprises an inflection region, and wherein the prismatic power in the inflection region is substantially similar to the prismatic power in a region adjacent the inflection region.

110. 1. A lens for use in combination with a frame for supporting said lens in a path of direct forward gaze forming a central axis of one eye of a typical wearer in non-corrective eyewear or headgear, comprising: A lens body, a front surface having one of a toric and a freeform shape; a posterior surface having the other of the toric and freeform shapes; Lens body including Including, a visual axis extends from the eye and the central axis at an angle from the central axis away from the typical wearer's nose, measured along the posterior horizontal meridian; Each point along the horizontal meridian of the posterior surface is associated with an angle of the visual axis at which the visual axis intersects with each point along the horizontal meridian of the posterior surface; and A lens having a prismatic power of about 0.44 diopters or less throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees or less.

111. 111. The lens of claim 110, wherein the prismatic power of the lens is less than or equal to about 0.64 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 40 degrees.

112. 111. The lens of claim 110, wherein the prismatic power of the lens is less than or equal to about 0.89 diopters throughout points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 50 degrees.

113. 111. The lens of claim 110, wherein the difference between the maximum and minimum prism powers of the lens is less than or equal to about 0.18 diopters throughout a range of points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees to about 40 degrees.

114. 111. The lens of claim 110, wherein the difference between the maximum and minimum prism powers of the lens is less than or equal to about 0.43 diopters throughout a range of points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees to about 50 degrees.

115. 1. A lens for use in combination with a frame for supporting said lens in a path of direct forward gaze forming a central axis of one eye of a typical wearer in non-corrective eyewear or headgear, comprising: a front surface having a spherical, toric, cylindrical or freeform shape; A rear surface having a freeform shape. Including, the spherical, toric, cylindrical or freeform shape of the front surface has a horizontal base curve of about 6 curves or more; a visual axis extends from the eye and the central axis at an angle from the central axis away from the typical wearer's nose, measured along the posterior horizontal meridian; Each point along the horizontal meridian of the posterior surface is associated with an angle of the visual axis at which the visual axis intersects with each point along the horizontal meridian of the posterior surface; and A lens, wherein the difference between maximum and minimum prism powers of the lens is less than or equal to about 0.18 diopters throughout a range of points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees to about 40 degrees.

116. 116. The lens of claim 115, wherein the anterior surface has a toric shape and a horizontal base curve of about 6 curves, and the difference between the maximum and minimum prism powers of the lens is less than or equal to about 0.60 diopters throughout a range of points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 40 degrees.

117. the spherical, toric, cylindrical or freeform shape of the front surface has a horizontal base curve of approximately 8.75 curves; and 116. The lens of claim 115, wherein the difference between the maximum and minimum prism powers of the lens is less than or equal to about 0.70 diopters throughout the range of points along the horizontal meridian of the posterior surface associated with angles of the visual axis of less than or equal to about 40 degrees.

118. 116. The lens of claim 115, wherein the difference between the maximum and minimum prism powers of the lens is less than or equal to about 0.40 diopters throughout a range of points along the horizontal meridian of the posterior surface associated with angles of the visual axis of about 30 degrees to about 50 degrees.

119. 119. The lens of claim 118, wherein the spherical, toric, cylindrical or freeform shape of the anterior surface has a horizontal base curve of approximately 6 curves.

120. 120. The lens of claim 119, wherein the anterior surface has a toric shape.

121. the lens is a single lens, the visual axis is a first visual axis, the eye is a first eye, The single lens is configured to be supported in a forward line of sight path that forms a central axis of a second eye of the typical wearer; a second visual axis extends from the second eye and the central axis of the second eye at an angle from the central axis of the second eye measured along the horizontal meridian of the posterior surface away from the typical wearer's nose in a direction opposite to the direction of the first visual axis; each point of a second set of points along the horizontal meridian of the posterior surface is associated with an angle of the second visual axis at which the second visual axis intersects the respective point of the second set of points; and 121. The lens of claim 120, wherein the prismatic power of the lens is less than or equal to about 0.44 diopters throughout the points of the second set of points associated with angles of the second visual axis less than or equal to about 30 degrees.

122. 122. The lens of claim 121, wherein the posterior surface further comprises an inflection region, and wherein the prismatic power in the inflection region is substantially similar to the prismatic power in a region adjacent the inflection region.

Images