Peripheral quadrant design contact lens

Abstract

A contact lens, which can be any of a conventional hard contact lens, a corneal corrective lens, a scleral lens, or a soft contact lens, has one or more peripheral annular zones adjacent to and radially outward from a central optical zone of the contact lens. The peripheral annular zones include an alignment zone for directional control, upright control, or peripheral alignment to improve the molding effect of a corneal corrective lens, the comfort or vision quality of a conventional RGP, a scleral contact lens, or a soft contact lens. The elevation of the lens along one sub-axis in the alignment zone is different than the elevation of the lens along at least one other sub-axis.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 63,037,547, filed on June 10, 2020. The disclosure of the foregoing application is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to peripheral quadrant design contact lenses. Background Art

[0004] Many people experience vision problems due to a variety of possible conditions. The most common vision problem is a condition called myopia or nearsightedness. Myopia is a common condition in which the eye cannot focus on distant objects because the curvature of the cornea is too steep (i.e., the radius of curvature of the cornea is shorter than normal) to provide adequate focus on the retina of the eye. Another condition is called hyperopia or farsightedness. In the case of hyperopia, the eye cannot focus on objects far and near because the curvature of the cornea is too flat (i.e., the radius of curvature of the cornea is longer than normal) to provide adequate focus on the retina of the eye. Hyperopia is very common among young children. Severe hyperopia can induce lazy eye or amblyopia in childhood. Another common problem is astigmatism, in which the unequal curvature of one or more refractive surfaces of the cornea prevents light from focusing clearly on a single point on the retina, resulting in blurred vision. Presbyopia is the most common vision problem in adults aged 40 and above. Regardless of whether their distance vision is emmetropia, myopia, or hyperopia, people over 40 begin to experience difficulty focusing on close objects as the lens of the eye loses its elasticity. Presbyopia can develop and cause complications with other refractive problems such as hyperopia, myopia, or astigmatism.

[0005] A normal cornea is generally parabolic in shape, with the curvature being steepest (i.e., having a shorter radius) at or near the central portion of the cornea, and gradually flattening out (i.e., having a longer radius) toward the limbus with a positive e-value (or so-called "positive shape factor"). An aberrant cornea is a cornea that is significantly different from the normal parabolic shape, with a sudden protrusion of the human cornea or a "negative shape factor," which may occur naturally or be caused by refractive surgery. The former case (i.e., "natural variation") is best demonstrated by keratoconus, while the latter case (i.e., due to surgery) is best exemplified by myopic refractive surgeries such as LASIK, PRK, and RK.

[0006] While modern spectacles, contact lenses, intraocular lenses, refractive surgery, corneal cross-linking, and implantable intracorneal ring segments (e.g., the Intac corneal ring) have provided improvements for keratoconus and post-refractive surgery failures, there remains a need for designs of optical devices, or more specifically, designs of hard and soft specialty contact lenses, scleral spectacles, and orthokeratology ("orthokeratology") spectacles that can better correct all of the above conditions.

[0007] The parabolic ocular surface of the cornea and its adjacent scleral portion are not always regular or symmetrical in shape. Corneal or scleral irregularities may result from corneal trauma, refractive surgery, corneal transplantation, or ocular diseases such as keratoconus or limbal degeneration. Even if the ocular surface is essentially normal, the corneal or corneoscleral contour may still be highly toric or tilted, affecting spectacle centration, visual quality, and orthokeratology shaping results. The former situation (i.e., the "irregular" corneal surface) may require a scleral lens covering the entire cornea and resting on the scleral portion to form a new regular refractive surface to correct vision in various difficult conditions. The new refractive surface may require further correction by adding an anterior toric shape to the anterior optical zone to correct for internal astigmatism or by increasing the axial thickness in one or more quadrants of the lens. Both situations require locking and stabilizing the lens orientation.

[0008] In the latter case (i.e., a highly toric / tilted but generally normal cornea or corneoscleral surface), locking the eyeglass orientation may be desirable for a variety of reasons, including but not limited to incorporating a toric power on the anterior optical zone for conventional RGP or scleral eyeglasses to correct residual astigmatism, or for orienting the optical zone 22 and / or centering the eyeglasses when placed on a tilted or highly toric cornea during orthokeratology.

[0009] It is known to orient the lens by methods such as prismatic ballasting or truncation, which is done by forming a thicker rim in a soft or hard contact lens so that the thicker side is pulled downward with the thicker rim to control rotation, and this has been widely used in the hard and soft toric contact lens industry. Prismatic ballasting works well in daily wear contact lenses to provide orientation control by gravity rather than relying on conforming to the shape of the cornea for orientation. However, prismatic ballasting can cause significant irritation to the eye and does not work in the supine position (such as orthokeratology where the lens is worn while sleeping). Another method is to have the eyelids grip the lens for orientation control, which has been widely used in soft toric contact lenses, which form one or two thinner or flexible rims against the eyelids to control lens orientation by holding the thinner lens rim between the eyelids.

[0010] Another method of controlling lens orientation, described in U.S. Patent No. 7,296,890, uses a single-component lens with four sets of base curves and four corresponding sub-axes to create a posterior surface that conforms to the measured corneal shape. This method controls the orientation of the lens by conforming the lens to match the measured corneal surface, allowing further design to be incorporated into the anterior optic zone if it is desired to lock the lens for orientation control. While this method is suitable for orientation control, it is not suitable for orthokeratology, which requires a defined base curve for corneal shaping and therefore cannot be set to conform to the central corneal shape for orientation control. This "central quadrant design," which combines multiple base curves with sub-axes in the central portion of a daily wear contact lens, may cause undesirable residual astigmatism when the contact lens is worn and may complicate the lens prescription to be ground on the anterior optic zone of the lens. Summary of the Invention

[0011] The present invention relates to vision science and methods for designing devices and contact lenses for fitting contact lenses and orthokeratology for myopia correction and control, hyperopia, presbyopia, and more specifically, for managing corneal astigmatism or corneal variations (such as keratoconus or failed refractive surgery). The present invention can be applied to the production of hard contact lenses, orthokeratology lenses, scleral lenses, and soft contact lenses in which the posterior surface of the middle and / or peripheral regions of the lens has different sagittal heights in one or more than one sub-axis or quadrant (peripheral quadrant design, or P-Qdrt) so that the lens sagittal heights in all sub-axis or quadrants can be more accurately adapted to the patient's ocular surface to reduce rotation or tilt on the eye 10. The medial and peripheral curves of the P-Qdrt toric RGP contact lens can be spherical or aspheric, with multiple sub-axes, curvatures, or eccentricity values, while the curvature of the base curve (i.e., the central curve of the posterior surface of the contact lens 20) is rotationally symmetrical, spherical or aspheric, allowing the laboratory to easily add the desired toric power and / or lens axial thickness to its anterior surface in a fixed orientation to achieve clear vision and stable astigmatism correction. Although the central base curve is made rotationally uniform through 360 degrees, this is independent of the contact lens's directional control. In addition to lens orientation, the P-Qdrt contact lens also aids orthokeratology shaping by providing a better water seal in the alignment zone 26 to apply a stronger peripheral inward thrust, particularly for shaping toric or tilted corneas. The present invention also includes a method for creating a P-Qdrt trial lens set to double-check corneal sagittal height (particularly within the sub-axes) obtained from measurement equipment (including but not limited to corneal topography, 3D mapping, or OCT) during lens design.

[0012] The object of the present invention is to provide a method for creating a hard contact lens, orthokeratology lens, scleral lens or soft contact lens for a variety of purposes. The first object of the present invention is for directional control of contact lenses that require fixed orientation to combine cylindrical power with an axis on the front optical zone 31, or to provide additional lens axial thickness in one or more fixed quadrants, or for orthokeratology reshaping on a toric cornea with internal astigmatism that requires a toric or asymmetric base curve to shape a fixed sub-axis or quadrant to correct the internal astigmatism. The present invention, known as the peripheral quadrant design (P-Qdrt), can lock the lens orientation for directional control without affecting the base curve or central back curve of the contact lens 20 that conforms to the measured cornea. The base curve of the central back surface of the P-Qdrt orthokeratology contact lens 20 is typically designed to be a spherical or aspheric curvature that is uniform through 360 degrees of rotation. The optical zone 22 can also be created toric, oblique, or quadrant, but with a sub-axis of curvature that does not conform to the measured cornea, its base curve can be flatter or steeper than the corneal curvature, and its axis can be opposite to or skewed relative to the axis of corneal curvature. The uneven (toric, oblique, or quadrant) optical zone 22 thus created for orthokeratology shaping, together with the P-Qdrt alignment zone 26 for orientation control, can be used to eliminate internal astigmatism or crystalline astigmatism, forming a new corneal toric surface that is different from the original cornea. Thus, the present invention enables control of the lens orientation through the periphery of the P-Qdrt lens, freeing the central optical zone 22 and its base curve for functions other than orientation control. The optical zone 22 and its base curve of the present invention can be designed to not conform to the central corneal shape while still utilizing the peripheral alignment zone 26 to control the lens orientation for orthokeratology shaping of corneas with internal astigmatism.

[0013] Another object of the present invention, referred to as "Erecting Control," is to provide orthokeratology contact lenses, conventional RGP lenses, scleral lenses, or soft contact lenses, with multiple sets of sagittal heights and sub-axes to allow the optical center to be aligned on a toric or tilted cornea. The optical center must intersect the corneal apex tangentially to achieve better orthokeratology treatment and clearer vision.

[0014] Yet another object of the present invention is to provide a corneal reshaping contact lens, conventional RGP lens or scleral lens having multiple sets of sagitta and sub-axes to bear on the peripheral portion of the cornea or sclera more closely, which is called peripheral alignment. The sagitta of each sub-axis is predetermined by measured corneal or ocular information and / or by trial fitting using a standard eyeglass test set, wherein the specifications of the trial eyeglasses are predetermined and well known to eye care personnel (ECP). The sagitta differences of the sub-axes used for peripheral alignment are accounted for in the alignment zone 26 of the contact lens 20, which is adjacent to and radially outward from the central optical zone 22 or the intermediate zone 24 of the contact lens 20. The P-Qdrt lens with peripheral alignment does not need to conform to the central or peripheral portion of the cornea 12 or ocular surface of the eye 10, while still significantly improving centering and water seal by more closely fitting the peripheral portion of the contact lens 20 to the peripheral portion of the cornea 12. P-Qdrt lenses for peripheral alignment are particularly useful in orthokeratology shaping of corneas 12 that are highly toric, tilted, or irregular to improve the peripheral water seal. The alignment area 26 so formed can apply a more effective inward push to the peripheral portion of the cornea 12 for inward shaping. It also helps design P-Qdrt conventional RGP or scleral contact lenses to better center on highly toric or irregular corneas by aligning the contact lens more closely on the irregular corneal or scleral surface. If ECPs routinely check corneal elevation maps using reliable topography and factor them into P-Qdrt lenses for upright control or peripheral alignment, they can save office time and prevent problems by reducing lens changes.

[0015] The objectives of the present invention are achieved by providing a P-Qdrt eyewear that utilizes the disclosed method to determine multiple sets of corneal sags within a sub-axis of the cornea 12 or ocular surface of the eye 10 and implements the sag information into an alignment region 26 for directional control, upright control, or peripheral alignment. The P-Qdrt design can improve the shaping effect of orthokeratology lenses or the visual quality of conventional RGP spectacles, scleral spectacles, or soft contact lenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic side view of a P-Qdrt contact lens in accordance with the present invention in use with the cornea of ​​a patient's eye.

[0017] Figure 2 is a front plan view of an embodiment of a P-Qdrt contact lens of the present invention showing four sets of alignment zone sub-axes.

[0018] Figure 3 1 is a front plan view of another embodiment of the P-Qdrt contact lens of the present invention, which shows four sets of alignment zone sub-axes.

[0019] Figure 4 and Figure 5 Eye elevation is illustrated using the following anterior corneal surface sagittal information (BFS: central corneal radius 7.67 mm; eccentricity value: 0.46):

[0020] Height (μ) / sub-axis BFS 0° 90° 180° 270° Arrow height (μ) 2731 2494 2613 2973 2851 Elevation to BFS(μ) 0 237 119 -242 -120

[0021] Figure 4 The eye elevation heights referenced to the best fit sphere (BFS) of the cornea along sub-axes 0°-180° are shown, which can be used to derive the sagittal heights and curves of the alignment zones of the present contact lenses.

[0022] Figure 5 The eye elevation heights are shown referenced to the best fit sphere (BFS) of the cornea along sub-axes 90°-270°, which can be used to derive the sagittal height and curve of the alignment area of ​​the contact lens.

[0023] Figure 6 is used Figure 4 A side cross-sectional view along the 0°-180° sub-axis of a contact lens designed for eye height is shown, having different lens sags at the edge.

[0024] Figure 7 is used Figure 5 Side cross-sectional view along the 90°-270° sub-axis of a contact lens designed for eye height, with different lens sags at the edge, is shown.

[0025] Figure 8 is a flowchart of a process for determining P-Qdrt data for manufacturing a P-Qdrt contact lens for fitting or treatment according to the present invention.

[0026] Figure 9 is a diagram illustrating a client-server networking environment in which the present invention may be implemented.

[0027] The reference numerals in the drawings have the following meanings.

[0028]

[0029] DETAILED DESCRIPTION

[0030] The following detailed description is the best mode currently contemplated for carrying out the present invention. This description is not intended to be limiting, but is merely for the purpose of illustrating the general principles of the present invention. The scope of the present invention is best defined by the appended claims.

[0031] definition

[0032] As used herein, the following terms and variations thereof have the meanings given below, unless the context in which the term is used clearly indicates a different meaning.

[0033] "Irregular toric" refers to a regular toric cornea in which the two principal meridians are perpendicular to each other, but the horizontal meridian is more curved than the vertical meridian, where the horizontal meridian means a range of 0 to 30 degrees, or a range of 150 to 180 degrees.

[0034] "Against the rule tilt" refers to a cornea with the tilt axis on the vertical meridian, where the meridian is defined as 60 to 120 degrees. "With the rule tilt" refers to a cornea with the tilt axis on the horizontal meridian, where the meridian is defined as 0 to 30 degrees or 150 to 180 degrees.

[0035] The "axial thickness" of a contact lens at a point radially outward from the geometric center of the contact lens refers to the axial distance between the front and back surfaces of the lens at that point on the contact lens 10, which can be determined by subtracting the sagitta of the front surface from the sagitta of the back surface at that point and then adding the center thickness of the contact lens.

[0036] "Refractive error" refers to a refractive error in a subject's vision, i.e., an error in the eye's focus on light that results in altered or reduced visual acuity. Examples of refractive error include myopia, hyperopia, and astigmatism.

[0037] "Back curvature" refers to the curvature of the back (posterior) surface of a contact lens (ie, the surface that contacts the subject's eye).

[0038] "Base curve" means the curve or curves of the central portion of the posterior surface or optic zone in a contact lens.

[0039] The Best Fit Sphere (BFS) is a sphere calculated using the least mean square deviation method for elevation maps.

[0040] "Center thickness" is the distance between the front and back surfaces of a contact lens at the geometric center of the contact lens.

[0041] "Central corneal astigmatism" can be divided into regular astigmatism and irregular astigmatism. Regular corneal astigmatism is rotationally symmetric about the corneal apex, but the curve is not rotationally uniform. In this case, the principal meridians of the cornea are always 90° apart from each other, and the refractive power will vary continuously from one meridian to the other. Each meridian in an eye with regular astigmatism has a uniform curvature at every point along that meridian as it crosses the pupil entrance. In irregular astigmatism, the principal meridians are separated by any angle other than 90°, that is, they are not perpendicular to each other. In this type, the curvature at each meridian is not uniform, but varies from one point to another across the pupil entrance. A small amount of irregular astigmatism can be seen in each eye when the entire cornea is evaluated; however, this is medically insignificant when the irregularity is located outside the pupil entrance.

[0042] The "central curve" is the radius of curvature of that portion of the contact lens that determines the lens' power.

[0043] A "central quadrant design" contact lens is a single-component contact lens having four sets of base curves on the central back surface of the lens, wherein each set of base curves is associated with a sub-axis, and all four sub-axes are 90 degrees or orthogonal to each other. As with the lens defined in U.S. Patent 7,296,890, the four sets of base curves and sub-axis combinations are determined to conform to the measured shape of the cornea for lens orientation.

[0044] "Edge thickness" refers to the axial thickness measured at the most peripheral portion of a contact lens. Edge thickness can be calculated by adding the front sagitta and center thickness of the lens and subtracting the back sagitta.

[0045] "E value" refers to a measure of corneal eccentricity, with a value of zero indicating a perfectly spherical cornea. A negative e value indicates a flat central region with a steep mid-periphery (oblate surface), while a positive e value indicates a surface that is steep in the center and flattens radially outward (prolate surface).

[0046] "Front curvature" refers to the curvature of the front surface of a contact lens (ie, the surface facing away from the subject's eye).

[0047] "Anterior optical zone" means the centralmost portion of the anterior surface of a contact lens extending radially outward from its geometric center to the peripheral junction. The anterior optical zone may have an anterior curvature known as a "power curve."

[0048] "Anterior peripheral zone" means an annular anterior surface coupled to and extending radially outward from the anterior optic zone, having an anterior curvature referred to as the "anterior peripheral curve."

[0049] "Oblique astigmatism" refers to a regular toric cornea in which the two principal meridians are not horizontal or vertical, but are perpendicular to each other, with meridians ranging from 30 to 60 degrees, or 120 to 150 degrees.

[0050] "Optical zone" means the centralmost portion of a contact lens extending radially outward from its geometric center to the peripheral junction, the curvature of the posterior surface of which is referred to as the "base curve."

[0051] The terms "orthokeratology" and "orthokeratology" refer to the planned application of a series of contact lenses to a patient to improve vision by reshaping the cornea.

[0052] "Orientation angle" refers to a number of angles between 0° and 360° that indicate the orientation of the eyeglasses on the cornea or corneal topography. When facing the corneal surface or topography, the orientation angle increases counterclockwise from 0° to 360°. 0° is set to the examiner's right (e.g. Figure 2 and Figure 3 ), then counterclockwise and orthogonal to 0° is 90° on the superior side, further counterclockwise and mirrored to 0° is 180°, then further counterclockwise to 90° is mirrored to the inferior side at 270°. If the corneal toricity or tilt is deviated, the 0° direction can be set to tilt relative to the horizontal meridian and rotated counterclockwise from the deviated 0° angle as previously described.

[0053] "Orientational control" of a contact lens means limiting the rotation of the lens while it is worn on the eye, for example allowing the cylindrical power or thicker section of the lens to be stably oriented on a desired axis.

[0054] "Peripheral ocular irregularity" refers to the assessment of annular irregularities outside the pupil entrance, which can be assessed radially outward to the corneal edge, limbal region, or adjacent sclera. Peripheral ocular irregularity of the cornea is typically determined by measuring an elevation map using corneal topography. The values ​​on the elevation map represent the height of the analyzed corneal surface relative to a reference surface. Trial fitting, topographers, or optical coherence tomography (OCT) can determine ocular irregularities up to the adjacent sclera.

[0055] A "Peripheral Quadrant Design" (P-Qdrt) contact lens is a multi-component lens having a base curve for the central optical zone 22 portion of the contact lens 20, wherein the base curve is not designed to conform to the measured shape of the cornea for directional control, but rather can be formed in any geometrically possible shape required for orthokeratology shaping or optical correction. The lens includes at least an alignment zone 26 having four sets of alignment curves forming an annular peripheral portion of the posterior surface of the contact lens 20, extending radially outward from the junction with the optical zone 22 having the base curve, or from the junction with the intermediate zone 24, wherein each set of alignment curves is associated with a sub-axis, wherein the four sub-axes are separated by 90 degrees or orthogonal to each other. The four sets of alignment curves within the sub-axes are carefully determined so that the peripheral portion of the lens fits snugly against the peripheral portion of the ocular surface, and all alignment curves are connected with a gradual curvature to form an uneven but smooth and continuous annular alignment zone 26.

[0056] The term "peripheral alignment" refers to the use of the peripheral quadrant design (P-Qdrt) contact lenses of the present invention, in which the lens sagitta of each sub-axis matches the eye sagitta in each corresponding sub-axis, so that the peripheral portion of the contact lens fits tightly against the peripheral portion of the corneal or scleral surface to form a water seal, which is important for adapting orthokeratology, RGP and scleral lenses to irregular corneas or sclera.

[0057] "Power curve" means the curve or curves on the central portion of the front surface or anterior optic zone in a contact lens.

[0058] A "hard contact lens" is a contact lens whose surface does not change shape to follow the contours of the corneal surface. Hard lenses are typically made from PMMA (poly(methyl methacrylate)) or from gas-permeable materials such as silicone acrylates, fluoro / silicone acrylates, and cellulose acetate butyrate, whose primary polymer molecules generally do not absorb or adsorb water.

[0059] "Sagitta" refers to the height of a tangent plane passing through the geometric center of the back surface of a contact lens or the front surface of the ocular surface, where the height is measured from the apex of the dome to the plane of the area of ​​the contact lens or ocular surface to be measured. The sagitta of a contact lens may refer to the front sagitta or the back sagitta. The front sagitta of a lens at a certain point means the vertical distance measured from the front surface at that point to the horizontal plane that intersects the outermost edge of the front surface of the lens. The back sagitta of a lens at a certain point means the vertical distance measured from the back surface at that point to the horizontal plane that intersects the outermost edge of the back surface of the lens. In the absence of a reference, "sagitta" generally means the back sagitta.

[0060] "Scleral lenses," also known as scleral contact lenses, are larger, hard contact lenses that completely bridge the cornea and rest against the sclera, creating a tear-filled space between the back surface of the lens and the cornea.

[0061] A "soft contact lens" is a contact lens formed from a material whose surface generally follows the contours of the corneal surface when placed on the cornea. Soft contact lenses are typically made from materials such as HEMA (hydroxyethyl methacrylate) or silicone hydrogel polymers, which contain approximately 20-70% water.

[0062] The "thickness differential" of a meridian or quadrant refers to the difference in axial thickness found by comparing the thickest portion of the thicker meridian or quadrant to the thinnest portion of the thinner meridian or quadrant of a contact lens.

[0063] "Tilt" relative to the cornea or sclera means that the ocular surface (including the cornea and / or adjacent sclera) has different elevations in one or more quadrants, so that the curvature of the meridian passing through the geometric center of the cornea is not rotationally symmetric. The meridian passing through the geometric center of the cornea that separates the steeper half and the flatter half is the "tilt axis". The tilt of the cornea or sclera can be measured using commercially available equipment, including but not limited to topography, 3D maps or OCT. The elevation of the tilted cornea can be determined by topography up to a 6-10 mm area width, and the measured information can be incorporated into the peripheral quadrant design (P-Qdrt) of conventional RGP and orthokeratology glasses. For scleral glasses or soft contact lenses, trial glasses or OCT can be used to determine the scleral tilt up to a 15-22 mm area width.

[0064] "Upright control" refers to the use of the peripheral quadrant design (P-Qdrt) contact lenses of the present invention, in which the lens sag of each sub-axis is matched to the sag of the eye in the corresponding sub-axis so that the geometric center of the contact lens can intersect the geometric center of the corneal vertex to obtain upright and tangential positions, which is important for fitting orthokeratology, RGP or scleral lenses on irregular corneas or sclera.

[0065] "Follow-the-rule astigmatism" refers to a regular toric cornea in which the two principal meridians are perpendicular to each other, but the vertical meridian is more curved than the horizontal meridian, where the vertical meridian is defined as a range of 60 to 120 degrees.

[0066] A "zone" is a partial or complete circumferential area of ​​a contact lens. A "quadrant" refers to a portion of such a zone. Typically, a zone will also have a back surface comprising a back curve having a specific radius of curvature with or without an e-value. However, a zone may also comprise multiple curvatures having a specific e-value or forming one or more specified curvatures (e.g., an aspheric curve or an S-curve).

[0067] As used herein, the term "comprise" and variations of the term, such as "comprising" and "comprises," are not intended to exclude other additives, components, integers, or steps. The terms "a," "an," and "the," and similar referents used herein should be construed to cover both the singular and the plural, unless their usage in context indicates otherwise. Terms of position or distance, such as "horizontal," "vertical," "upper," "lower," etc., are intended to be relative terms unless otherwise indicated.

[0068] equation

[0069] The "sag equation (S)" is given by S = R / P - SQRT ((R / P) 2 -(D / 2) 2 / P) where R is the measured central curvature of a spherical or aspherical surface; D is the area diameter of the surface; e is the e-value of the surface; and P is derived from the equation P = 1-sign(e)*e 2 Derived from e.

[0070] The "Oblique Astigmatism" equation estimates the oblique astigmatism (in diopters) for a toric power of T. The equation for an angle of deviation X° is O = T*SIN((X°)*PI() / 180)^2. The equation for oblique astigmatism (P) at an angle orthogonal to angle X° is P = T*COS((X°)*PI() / 180)^2.

[0071] Determine the “annular area sagittal height” (S az ) is S az =S2-S1, where the outer radius sag of the area is S2 and the inner radius sag of the area is S1.

[0072] The equation for converting sag to curvature is: Radius of curvature = SQRT(((S 2 +(D2 / 2-D1 / 2) 2 +D1*(D2 / 2-D1 / 2)) / 2) 2 / S 2 +(D1 / 2) 2 )), where "D2" is the area width of the outer area, "D1" is the area width of the inner area, and S is the vector height of the annular area between the outer area and the inner area.

[0073] Detailed description

[0074] The present invention is directed to a contact lens and a method for manufacturing the same. More specifically, the present invention relates to a contact lens that provides a design for the peripheral portion of the lens to achieve directional control, upright control, or peripheral alignment. The central optical zone of the lens is freed up to be freely predefined to any desired geometry for orthokeratology shaping or vision correction, without having to conform to the shape of the central cornea.

[0075] Figures 1 to 3 as well as Figures 6 and 7 A P-Qdrt contact lens 20 is illustrated according to one embodiment of the present invention. The contact lens 20 has an optical zone 22, an optional intermediate zone 24 ( Figure 3 ), alignment area 26 and peripheral area 28. Figure 1 As shown, the contact lens 20 is a P-Qdrt contact lens adapted to be worn on the cornea 12 of the patient's eye 10. Examples of elevation information for such a lens are shown in FIG. Figure 4 and Figure 5 Shown in.

[0076] A spherical coordinate system may be used to describe the shape of the contact lens 20 . Figure 2 and Figure 3 A contact lens 20 is illustrated having an X-axis 41, a Y-axis 42, and a Z-axis 43, which axes may be optical axes when the lens is worn on the eye, such as Figure 1 Each axis is preferably orthogonal (perpendicular) to one another, such that a ninety-degree angle exists between each axis and any two such axes lie in the same plane. X-axis 41 and Y-axis 42 lie in a plane in which the lowest point of the contact lens edge is also located. The coordinate system described by X-axis 41, Y-axis 42, and Z-axis 43 is a Cartesian coordinate system.

[0077] Each axis 40 can be subdivided into two sub-axes 50. For example, the X-axis 41 can be divided into a first sub-axis 51 and a second sub-axis 52, and the Y-axis 42 can be divided into a third sub-axis 53 and a fourth sub-axis 54. Figure 2 and Figure 3 Thus, each axis comprises two opposite radial lines extending from the intersection of the axes.

[0078] The contact lens 20 has an alignment region 26 and is Figure 2 and Figure 3As can be seen in FIG, sub-axes 51 to 54 can be said to divide the alignment region 26 into four quadrants 60, namely a first quadrant 61 (Q1), a second quadrant 62 (Q2), a third quadrant 63 (Q3), and a fourth quadrant 64 (Q4). The posterior curvature and sag of the alignment region 26 are different from the posterior curvature and sag of the optic zone 22 of the contact lens 20. In addition, each of the sub-axes 51 to 54 can have a different curve and a different sag in the portion of the sub-axes located within the alignment region 26, with at least one sub-axis in the alignment region having a predetermined sag and / or curvature that is different from the sag and / or curvature of at least one other sub-axis in the alignment region. The posterior curves within the quadrants 60 of the alignment region 26 between adjacent sub-axes (e.g., between sub-axes 52 and 54) are connected to achieve a smooth, circular alignment curve for the posterior surface of the contact lens 20, as known to those skilled in the art (e.g., engineers programming lathes for cutting contact lenses). In one embodiment, the back curvature and / or sag of three quadrants are the same, while one quadrant is different. Alternatively, the back curvature and / or sag of all four quadrants can be different from each other. In combination, for example, the back curvature and / or sag of the quadrants can be as follows: Q1 = Q3 and Q2 = Q4 but Q1 and Q3 ≠ Q2 and Q4; (2) Q1 = Q2 and Q3 = Q4 but Q1 and Q2 ≠ Q3 and Q4; (3) Q1 = Q2 = Q3 ≠ Q4; (4) Q1 ≠ Q2 ≠ Q3 ≠ Q4; (5) Q1 ≠ Q3 but Q2 = Q4; and (6) Q1 ≠ Q2 but Q3 = Q4.

[0079] The optical zone 22 of the orthokeratology contact lens 20 for reducing myopia has a curvature defined by a base curve 30, wherein the optical zone 22 applies the primary compressive force to an area centered substantially on the apex center of the cornea 12 and is responsible for correctively flattening the central portion of the cornea 12 or reducing the radius of curvature during treatment. The radius of curvature of the base curve 30 is greater than (longer or flatter than) the measured curvature of the central portion of the cornea 12 and produces a central fitting area that applies the primary compressive force during vision correction. In other words, the curvature of the base curve 30 is flatter than the measured curvature of the central portion of the cornea 12. In one embodiment of the P-Qdrt orthokeratology lens for correcting myopia of the present invention, the diameter of the optical zone 22 ranges from 3 mm to 10 mm, and the radius of curvature of the base curve 30 ranges from 15.0 mm to 7.0 mm.

[0080] The optical zone 22 of the orthokeratology contact lens 20 for alleviating hyperopia has a curvature defined by a base curve 30. The optical zone 22 forms a suitable space for shaping tissue to an area substantially centered on the apex center of the cornea 12 and is responsible for correctively steepening the central cornea or increasing the radius of curvature during treatment. The radius of curvature of the base curve 30 is smaller than (shorter or steeper than) the measured curvature of the central portion of the cornea 12 to treat hyperopia, thereby creating a central bulge to provide a suitable space for corneal tissue to accumulate during vision correction.

[0081] The optical zone 22 of the present invention can be divided into two parts to treat presbyopia with either myopia or hyperopia. In this embodiment, a relatively small inner optical zone 23 is used, having an inner optical base curve that is 1-4 diopters steeper (shorter radius) than the continuous base curve 30. The outer optical zone 22 defined by the base curve 30 is 1-15 diopters steeper (shorter radius) than the central curvature of the cornea 12. The spacing of the ridges below the outer optical zone 22 causes the cornea to be shaped to form a steeper near-central portion of the cornea 12 to correct hyperopia, and the even steeper inner optical zone 23 causes an even steeper central curvature of the cornea 12 to correct presbyopia. The inner optical zone 23 is preferably kept small enough to prevent it from obstructing distance vision, typically measuring 0.5 mm to 1.5 mm. Instead of dividing the optical zone to alleviate presbyopia, an aspheric base curve 30 may be created with a positive eccentricity (e-value) such that the curvature of the inner portion of the base curve 30 will be substantially steeper than the curvature of the outer portion of the base curve 30 .

[0082] Understanding the peripheral contours of the eye is important for designing contact lenses, especially contact lenses made of hard materials, such as RGP, orthokeratology, and scleral lenses. It is well known to contact lens designers that the optical center (usually the geometric center of the contact lens) must coincide with the geometric center of the cornea 12 so that the optical axis of the contact lens can be aligned with the visual axis of the eye 10. Eccentric contact lenses may cause vision problems and discomfort, such as fluctuating vision, halos or glare, and eye irritation. In addition to centered the contact lens 20 well on the cornea 12, it is also necessary to keep the optical zone 22 of the contact lens 20 covering the center of the cornea in an upright position to intersect tangentially with the corneal vertex. In other words, the section of the optical zone 22 of the contact lens 20 should be orthogonal to the visual axis of the eye 10 for upright control, which is particularly important for orthokeratology and scleral lenses.

[0083] If the section of the optical zone 22 of the orthokeratology contact lens 20 is tilted and not orthogonal to the visual axis of the eye 10, the force exerted by the back surface of the contact lens 20 on the central portion of the cornea 12 will be unevenly distributed and form an inclined (tilted) treatment area, which may lead to astigmatism or an irregular surface with poor vision. Tilt-placing the optical zone 22 of a hard contact lens 20 (more specifically, if it is a scleral lens), even if the centering may be very good, will still lead to oblique astigmatism or corneal aberrations, which may seriously interfere with the vision of the subject when the contact lens 20 is worn. The ocular surface of the cornea and the adjacent sclera of the eye 10 are generally not rotationally symmetric in all meridians. Infinite combinations of curvature and eccentricity are possible in all meridians, quadrants or annular regions of the eye 10. Therefore, there is still a need for P-Qdrt contact lenses for significantly tilted corneas, especially for orthokeratology or scleral contact lenses.

[0084] There are a variety of ocular surface measurement devices commercially available to determine the shape of the eye and convert this measurement information into eyeglass design. In the peripheral quadrant design (P-Qdrt) eyeglasses of the present invention, the base curve 30 of the optic zone 22 does not conform to the central ocular surface of the eye 10. Instead, the present invention teaches that the corneal sagittal height is equalized in all sub-axes or quadrants by the alignment zone 26 of the contact lens 20, and the optic zone 22 of the contact lens 20 is upright for a rotationally uniform fit on the ocular surface of the eye 10.

[0085] The base curve 30 and peripheral zones of the contact lens 20 of the present invention can be predetermined for any purpose, such as being flatter or steeper than the central corneal curvature, or toric, but not conforming to the corneal shape, to perform orthokeratology shaping on the cornea 12 to correct myopia, hyperopia, or astigmatism, including internal astigmatism. A single, spherical or aspheric base curve 30, or any geometrically possible base curve, can also be predetermined for optical correction in conventional RGP spectacles, scleral spectacles, or soft contact lenses. By providing four sets of alignment curves within the sub-axes, adjacent to and radially outward from the optic zone 22 or intermediate zone 24, sagittal differences across all sub-axes or quadrants are incorporated into the alignment zone 26 of the posterior surface of the contact lens 20. These four sets of alignment curves and sub-axes are determined by sagittal calculations for directional and / or upright control, and can also provide for a tighter fit of the peripheral portion of the contact lens 20 against the peripheral portion of the ocular surface of the eye 10 to improve lens centering and peripheral alignment. The plurality of alignment curves are connected with a gradual curvature to form an uneven but smooth and continuous annular alignment area 26 .

[0086] Another object of the present invention is to provide a contact lens 20 for orientation control. Most conventional contact lenses are rotationally symmetrical and can rotate freely on the eye without orientation. The previous understanding of central quadrant design lenses was to orient the contact lens to produce astigmatism and / or axial thickness on the front surface of the contact lens. Central quadrant design orients the contact lens so that the base curve of the posterior central surface conforms to the central curvature of the corneal surface, thereby enabling the production of astigmatism or axial thickness on a fixed meridian or quadrant. This method can orient contact lenses for vision correction, but cannot be applied to orthokeratology lenses for corneal shaping, which also require lens orientation. If, for any reason, the base curve 30 of the orthokeratology contact lens 20 cannot be shaped to conform to the central cornea, the base curve will not be able to change the central portion of the cornea to the desired shape, for which the lens will apply the planned force via the base curve portion of the contact lens 20 to change the corneal shape. The optical zone 22 having the base curve 30 of the orthokeratology contact lens 20 is typically manufactured to be flatter than the central curvature of the cornea 20 for myopia reshaping or steeper than the central curvature of the cornea 20 for hyperopia reshaping. In more advanced orthokeratology procedures for presbyopia, the base curve 30 of the contact lens 20 must be progressively shaped to reshape multifocal vision for central near (CN) or central distance (CD).

[0087] Central corneal toricity can typically be formed into a spherical or non-toric central cornea using an orthokeratology contact lens 20 having a rotated spherical or aspheric optical zone 22 and base curve 30. Under very specific conditions, internal astigmatism may be present, which cannot be eliminated by a single spherical or aspheric base curve. In such cases, the optical zone 22 can be manufactured with a toric base curve 30 having an axis orthogonal to or offset relative to the axis of the corneal toricity, while the toric base curve is oriented in the alignment zone 26 using the P-Qdrt design of the present invention to reconstruct the central corneal toricity to differ in power and / or axis from the original cornea 20 to correct the internal astigmatism. In such cases, the base curve 30 of the optical zone 22 can be toric or quadrantal, but will not conform to the original central cornea 20 as described in prior art U.S. Patent No. 7,296,890.

[0088] The P-Qdrt lens of the present invention can provide directional control while releasing the base curve of the central posterior surface of the contact lens 20 into any shape desired for orthokeratology as described above. Directional control is needed in a variety of orthokeratology conditions, including but not limited to the profiling of highly toric or tilted corneas that require peripheral alignment in sub-axes or quadrants, and the above-mentioned orthokeratology cases with internal astigmatism, where the base curve 30 can be created toric, but with a different power or axis to eliminate residual astigmatism, without having to conform to the central shape of the cornea 12.

[0089] The P-Qdrt design of the present invention is also more convenient and has superior optical quality for directional control in conventional RGP and scleral lenses. The correction power of conventional RGP or scleral lenses is ground on the front surface of the contact lens (also called the "power surface"). The power equation for the front and back surfaces of the lens is P = [1000*(n2-n1)] / R, where P is the lens power in diopters, n2 is the refractive index of the material that the light enters, and n1 is the refractive index of the material from which the light comes. The refractive index n of the lens material (usually about 1.45-1.50) is significantly different from that of tears (n = 1.336) and the cornea (n = 1.3375). When a rigid lens is placed on the cornea 12, the tear fluid fills the optical zone 22. If the base curve is a rotational single spherical or aspheric curve, this may cancel out almost all of the corneal toricity because the refractive index of the tear fluid (1.336) is very close to the refractive index of the cornea (1.3375), and the refractive power between the interfaces can be ignored because n2≈n1 and P=[1000*(n2-n1)] / R≈0. A single base curve makes it simple and easy to obtain the lens power and residual astigmatism to be ground on the front surface of the contact lens 20. If, however, two or more base curves are used for directional control in the optical zone of a central quadrant design, the refractive index difference between the lens material and the tear fluid (e.g., 1.45 and 1.336) may be sufficient to induce astigmatism or aberrations in the sub-axes at the different base curves. A P-Qdrt lens having a single base curve provides a simpler, more predictable way to obtain the cylinder power to be ground on the power (front) surface of the contact lens 20 while still providing directional control of the alignment zone 26.

[0090] Yet another object of the present invention is to provide a contact lens 20 for controlled peripheral alignment. The peripheral profile of a contact lens is important in several respects, the most important of which in orthokeratology lenses is to provide a peripheral water seal for the peripheral portion of the contact lens 20 to fit on the peripheral portion of the cornea 12, thereby applying an effective inward thrust. The peripheral profile of conventional RGP lenses, scleral lenses, or soft contact lenses also requires peripheral alignment, but not to apply thrust for corneal shaping. Peripheral alignment is required for eyeglass centering to keep the central portion of the contact lens accurately aligned with the visual axis for clear vision. Peripheral alignment of contact lenses is also critical to the comfort and corneal health of various contact lenses, including conventional RGP, scleral and orthokeratology contact lenses, and various soft contact lenses.

[0091] Peripheral alignment can be used for eyeglass centering, and the base curve 30 or central optical zone 22 of the contact lens 20 can be made into any reasonable shape or sagittal height for different purposes, including but not limited to a curve that is flatter or steeper than the curve of the corneal curvature to fit or dome the central portion of the cornea 12, while the peripheral portion of various contact lenses must fit securely to the peripheral portion of the ocular surface for corneal shaping or vision centering. Conventional contact lenses typically utilize a nomogram for one or more gradually flattened intermediate zones to create the back surface of the contact lens, or alternatively utilize a single gradually flattened aspheric curve to blend multiple zones to gently and comfortably fit the lens to the peripheral portion of the cornea. The outermost zone (or peripheral zone 28) of the contact lens is typically designed to be slightly elevated from the ocular surface so that the peripheral curve provides fluid exchange, where the edge lift height and edge shape are critical for fluid exchange and can reduce irritation to the eye 10.

[0092] While most ocular surfaces are irregular, even in an apparently normal eye, portions of the cornea or sclera of the eye 10 may be toric or tilted in certain sub-axes or quadrants. Irregularity may increase suddenly in some ocular diseases, after surgery or trauma (e.g., keratoconus, pellucid marginal degeneration, after refractive surgery, or after penetrating keratoplasty (PKP) surgery, etc.). The nomogram used to form uniformly curved annular areas is not suitable for eyes with irregular peripheral ocular surfaces. A more sophisticated way is needed to measure ocular irregularities and properly adjust the contact lens, which is particularly important for the construction of the peripheral portion of the present contact lens 20, the purpose of which is to properly fit the contact lens 20 on the peripheral portion of the irregular ocular surface to achieve centering, ocular health and comfort on the eye 10.

[0093] Different types of contact lenses may require different peripheral alignment design features. Conventional RGP lenses (where the lens size is smaller than the cornea size) will require fluid exchange, such that a partial sagittal difference is preferably created among the sub-axes to achieve an incomplete water seal to allow fluid exchange in the vertical meridian. For above 3 diopters of with-the-rule corneal astigmatism, the corneal sagittal in the vertical meridian is significantly deeper than the corneal sagittal in the horizontal meridian, and a P-Qdrt periphery may be required, where only 30% to 80% of the elevation difference is filled to achieve better lens centering while leaving some tear space at the lens edge for fluid exchange.

[0094] In orthokeratology lenses for highly toric or tilted corneas, the lens size is smaller than the cornea size, but the alignment zone 26 of the contact lens 20 is designed to fit tightly against the peripheral portion of the cornea 12, providing a 360-degree rotational water seal without fluid leakage. If fluid leaks, corneal tissue will redistribute to the leaking area, which is typically located in the lower cornea, creating a smiley-face-like corneal topography and resulting in poor vision. Therefore, in orthokeratology, the P-Qdrt orthokeratology contact lens 20 must match nearly 100% of the elevation difference in all quadrants to achieve complete peripheral alignment.

[0095] A scleral contact lens 20 is always larger than the cornea 12 of the eye 10, and its lens sagitta is designed to be deeper than the eye sagitta to create a space between the posterior surface of the lens 20 and the anterior surface of the cornea 12. A scleral contact lens has at least three posterior curvatures: an optical zone 22, one or more intermediate zones 24, an alignment zone 26 for adjusting the sagitta, and a peripheral zone 28 for fitting the peripheral portion of the scleral contact lens 20 to the sclera of the eye 10. The entire optical zone 22 of the scleral contact lens 20, including its base curve 30, should be designed to bulge without contacting the entire cornea 12. The base curve 30 of the optical zone 22 can be designed to form any shape or curve between 50 and 400 microns of central tear layer space. The intermediate zone 24 and alignment zone 26, adjacent to and radially outward from the optical zone 22, are used to adjust the overall sagitta of the scleral contact lens 20 to cover the entire cornea in a dome-like manner, including and slightly extending beyond the limbus. The scleral contact lens 20 should not fit over any section of the mid-peripheral portion of the cornea 20. The alignment zone 26 connects radially outward to the peripheral zone 28, which contacts and gently fits over the bulbar conjunctiva over the scleral portion of the ocular surface of the eye 10. The peripheral zone 28 of the scleral contact lens 20 should contact the scleral portion of the eye 10 for gentle and tight peripheral alignment, while the edge of the scleral contact lens should not indent the overlying conjunctiva by more than 50% of the edge thickness, nor should it bleach blood vessels or restrict blood flow, and the lens edge should not lift to cause irritation. It is not uncommon for the adjacent scleral portion of the eye 10 to have a small bump known as the conjunctival macula or significant scleral toricity; in this case, a P-Qdrt design with multiple sets of alignment zone curves can more appropriately fit the peripheral zone 28 of the scleral contact lens 20 over the scleral portion of the eye 10. An alignment zone 26, located adjacent to and radially outward from the outer edge of the optical zone 22 or intermediate zone 24, is used to adjust the sag of the scleral contact lens 20 to create an appropriate tear space between the posterior surface of the scleral contact lens and the anterior surface of the cornea 12. A properly designed scleral lens should form a tear layer of 50 to 400 microns at the center, without conforming to the entire anterior surface of the cornea 12. The tear space should extend to and slightly beyond the limbus of the eye 10. For very irregular ocular surfaces, such as severe keratoconus, the posterior surface of the scleral lens may contact the cornea in one segment or quadrant but have excessive tear pooling in another. This can be adjusted using a P-Qdrt design with multiple sets of alignment curves to achieve a more uniform tear layer. The multiple alignment curves of the alignment zone 26 can be blended into a continuous, uneven, but relatively smooth, annular alignment zone 26.

[0096] The peripheral region 28 of a P-Qdrt hard contact lens 20 having a peripheral curve on the posterior surface is connected to and extends from the alignment region 26. The peripheral region 28 may have only a single set of curvatures, but in the case of connecting to the uneven alignment region 26 as described above, it will still be rotationally uneven. For hard contact lenses 20 (including but not limited to conventional RGP, orthokeratology, or scleral lenses), the anterior peripheral region of the contact lens 20 can be designed to be uneven to follow the posterior peripheral region 28 to form an edge with a rotationally uniform thickness. A hard contact lens 20 with a rotationally uniform edge thickness will be more comfortable than a hard contact lens with an uneven edge.

[0097] The size of the peripheral region of the soft contact lens is generally larger than the cornea 12 and covers the adjacent sclera portion of the eye 10 beyond the limbus. The peripheral region of the soft contact lens flexibly covers the cornea 12 and can have good centering even if the ocular surface is slightly irregular. However, if the ocular surface is extremely irregular (including but not limited to keratoconus, pellucid marginal degeneration, or ocular trauma involving the limbus or sclera portion of the eye 10), it is still necessary to design the P-Qdrt soft contact lens of the present invention to achieve better peripheral alignment. The P-Qdrt lens for peripheral alignment in the peripheral region of the soft contact lens is different from the structure in the traditional toric soft contact lens for directional control mentioned above. The peripheral region of the P-Qdrt soft contact lens uses multiple sets of predetermined corneal sagittal heights and sub-axes to create the peripheral contour of the soft contact lens, and the sagittal height difference can be achieved on the front surface or the back surface of the contact lens surface 20. The soft contact lens material is flexible, and the back surface shape can be transposed to the front surface, and vice versa. The edge (outer periphery) of the peripheral region of the P-Qdrt soft contact lens is preferably made rotationally uneven in edge thickness to complement the sagittal differences of the adjacent quadrants 60 and / or sub-axes 50. The anterior surface of the eye 10 wearing such a soft contact lens will become rotationally uniform in the anterior surface. Thus, the anterior peripheral curve of the anterior peripheral region in the peripheral region of the P-Qdrt soft contact lens is made rotationally uniform and does not follow the uneven curvature of the posterior surface, and vice versa, to produce an uneven anterior peripheral curve and a uniformly shaped posterior surface to obtain a complementary uneven edge thickness for peripheral alignment.

[0098] When designing such a lens, the sagittal height of the wearer's eye should be determined in all meridians or quadrants to infer the peripheral curve of the P-Qdrt contact lens 20. Regarding the "central quadrant design" described in prior art in U.S. Patent 7,296,890, the base curve of the contact lens is directly designed to conform to the measured corneal shape for orientation control. The peripheral quadrant design (P-Qdrt) design retains the central base curve for various purposes and uses the peripheral posterior surface or peripheral area of ​​the contact lens 20 for peripheral alignment, erection control, and orientation control.

[0099] The fitting process is to reconstruct the corneal profile using eye sagittal and elevation data obtained from a topographer, 3D maps, OCT, or a standard test set of glasses with known sagittal heights to design the contact lens 20 or peripheral area. We then use the sagittal and elevation data within the sub-axis to derive multiple sets of alignment curves for the sub-axis of the alignment zone 26.

[0100] The general concept for calculating sagitta when designing a P-Qdrt contact lens 20 is to obtain the corneal sagitta for all quadrants with sub-axes in a topographer. Alternatively, the eye sagitta can be derived from the measured corneal curvature and shape factor (i.e., e-value, p-value, or q-value), for which purpose we typically examine four quadrants up to the maximum reliable annular area. The formula for deriving the eye sagitta from the measured curvature and shape factor is well known to eyeglass designers. The corneal sagitta measured in this manner can be confirmed using a standard test set in which the eyeglass sagitta has been predetermined, as is known to practitioners.

[0101] When determining the eye sagitta so that a scleral lens fits properly on the scleral surface, conventional topographers cannot measure contours beyond the limbus. We can use trial glasses with predetermined eyeglass sagitta to test and reconstruct the corneal sagitta to design the P-Qdrt scleral contact lens 20. After trial wear, we can adjust the quadrant sagitta by observing peripheral edge lift, edge pinching, indentation, or tear layer thickness using a slit lamp and fluorescein staining or OCT (ocular computed tomography). Some new topographers can also be used to interpret the eye contour beyond the limbus and can be used in conjunction with the above-mentioned test group to determine the eye sagitta and elevation height difference in all quadrants or sub-axes on the eye 10 for designing the P-Qdrt scleral contact lens 20.

[0102] For the peripheral area of ​​the P-Qdrt soft contact lens of the present invention, the eye shape should be determined, for example, using a commercial topographer, 3D maps, OCT, or a trial lens set with different quadrant rim thicknesses to fine-tune the rim thickness, especially within the sub-axis.

[0103] In the P-Qdrt eyewear of the present invention, the sagittal elevation of the alignment zone 26 and the peripheral region of the contact lens 20 is preferably tailored to match the predetermined sagittal elevation and height difference of the measured corneal surface 12 or ocular surface of the user's eye 10 for all sub-axes and quadrants, so that when the lens is placed on the eye 10, it automatically rotates to lock securely in the correct orientation without requiring additional orientation design. A skilled eye care professional can interpret the lens fit by applying fluorescein dye when fitting a P-Qdrt hard contact lens to determine if it is a good fit and whether the peripheral portion of the lens is properly attached to the ocular surface. A drill point or line marking on one of the sub-axes of the hard or soft P-Qdrt lens (preferably at 6 o'clock (o / c) (below) on its front surface) can also be used for easier identification, but marking can be made at any designated sub-axis known to the eye care professional (ECP). The drill point or line marking is added to detect any small angle of deviation when the finished contact lens 20 or the peripheral region is placed on the eye 10. ECPs can adjust their prescriptions for the amount of astigmatism or axis of astigmatism incorporated into the anterior or posterior surface of a P-Qdrt hard contact lens 20 or the peripheral region of a soft contact lens that requires directionality control via the P-Qdrt design of the present invention.

[0104] Convert measured eye information to calculate sag . The ocular information required to design the P-Qdrt contact lens 20 of the present invention or the peripheral area is typically measured corneal information from a topographer, such as corneal curvature (KM), shape factors (e-value, p-value or q-value) and elevation height obtained from an elevation map. Commercially available topographers for corneal information are generally reliable for corneal contours within an area of ​​approximately 10 mm, and it is necessary to extrapolate or combine several images to obtain a composite image to expand the measurable area but still within the limbus. For areas outside the limbus, other equipment such as 3D maps or OCT can be used, but the reliability of the information may not be as good as that of a topographer. The measured corneal information of corneal curvature and e-value or p-value can be used to derive corneal sagitta using formulas familiar to skilled eyewear designers. Equation 1 can be applied to derive the corneal sagitta (S) of the cornea 12, which has a measured apical radius "R"; shape factor e-value = e and P = 1-sign(e)*e 2 ; and the area diameter "D". Corneal sagittal height S = R / P-SQRT((R / P) 2 -(D / 2) 2 / P). For each set of corneal sagitta with sub-axes, the apical corneal radius R and the e value (or p value) can usually be obtained in a steepest and a flattest meridian that are orthogonal to each other. The corneal sagitta of the two main meridians of the D area (S s and S f ) can be derived using Equation 1, where S s =Rs / P s -SQRT((R s / P s ) 2 -(D / 2) 2 / P s ) and S f =R f / P f -SQRT((R f / P f ) 2 -(D / 2) 2 / P f ). In order to determine the quadrant sagitta of the P-Qdrt glasses of the present invention, we also need to obtain the elevation heights for the height differences among the four quadrants in the elevation map. The elevation map of the cornea derives the elevation heights with reference to the "Best Fit Sphere" (BFS), which is calculated and extrapolated by the cornea. The system then calculates the area of ​​"relative elevation" or "relative depression" based on the deviation from the BFS, and the deviation value is expressed in microns. The height that is elevated above the BFS is positive, and the height that is depressed below the BFS is negative. The steeper sub-axis in the figure is usually represented by blue to indicate depression relative to the BFS, while the flatter sub-axis is represented by yellow or red to indicate elevation relative to the BFS. The relative values ​​of depression and elevation with reference to the BFS provide the S, S that can be obtained in the above method. s and S f The required information of the sag adjustment is used to derive the quadrant sags S1, S2, S3 and S4 within the sub-axis.

[0105] S1, S2, S3, and S4 are corneal sags to be converted into curves for forming the back profile of the P-Qdrt lens so that the peripheral portion of the lens matches the peripheral portion of the cornea 12 in the corresponding sub-axis. Although the central base curve 30 of the optical zone 22 is part of the lens sag of the P-Qdrt lens, it is not designed to conform to the central corneal shape, but is used for therapeutic or other functional purposes, such as orthokeratology, for which the base curve 30 of the optical zone 22 is predetermined before the peripheral profile of the P-Qdrt contact lens 20 is designed. The above equation 1 is used to determine the lens sag S of the optical zone. OZ , where if the base curve is spherical (P=1), the base curve BC and the optical zone width OZ are applied to S OZ =BC-SQRT(BC 2 -(OZ / 2) 2 ); or, if the optical zone 22 is a predetermined aspheric surface, the p value (P OZ ), S OZ =BC / P OZ -SQRT((BC / P OZ ) 2-(OZ / 2) 2 / P OZ If the optical zone 22 forms a complex surface for orthokeratology lenses that eliminate internal astigmatism, there may be two orthogonal base curves that can be calculated by Equation 1 for each sub-axis, such that S OZ1 =BC1 / P OZ1 -SQRT((BC1 / P OZ1 ) 2 -(OZ / 2) 2 / P OZ1 ), and S OZ2 =BC1 / P OZ2 -SQRT((BC2 / P OZ2 ) 2 -(OZ / 2) 2 / P OZ2 ).

[0106] The middle zone 24 of the orthokeratology lens for treating myopia, hyperopia and / or presbyopia, which is adjacent to and radially outward from the optical zone 22, is designed to have a corneal sag height (BFS) from the best fit. IZ The derived sagittal height S measured to the outermost portion of the intermediate region 24 is IZ . With area diameter D IZ BFS IZ The BFS can be obtained by using the R and P of the cornea 12 through the above equation 1. IZ =R / P-SQRT((R / P) 2 -(D IZ / 2) 2 / P). In one embodiment of the orthokeratology contact lens of the present invention, the sag height S of the middle area of ​​the contact lens 22 is IZ Designed to have a regional sag S IZ =BFS IZ -S OZ , then by IC=SQRT(((S IZ 2 +(D IZ / 2-OZ / 2) 2 +OZ*(D IZ / 2-OZ / 2)) / 2) 2 / S IZ 2 +(OZ / 2) 2 ))S IZ Convert to the middle curve IC.

[0107] For the most common design, both the optical zone 22 and the middle zone 24 have a single uniform curvature. When the sub-axes are 0°, 90°, 180°, and 270°, respectively, the sagittal height S of the peripheral back surface of the contact lens 20 isaz1 、S az2 、S az3 、S az4 You can use S az1 =S1-(S OZ +S IZ )+K1;S az2 =S2-(S OZ +S IZ )+K2;S az3 =S3-(S OZ +S IZ )+K3;S az4 =S4-(S OZ +S IZ )+K4. Where K1, K2, K3, K4 are factors used to fine-tune the sagittal height in each meridian, for example but not limited to, for P-Qdrt RGP that requires "partial peripheral alignment" to promote tear exchange, only 30% to 80% of peripheral alignment is required for centering or directional control. The degree of peripheral fit can be adjusted by K1 to K4. The K1 to K4 factors can also be used to correct undesirable corneal fit, conjunctival squeezing or excessive edge lift in the scleral contact lens 20 to increase or decrease the edge lift in one or two quadrants so that the peripheral area fits properly on the ocular surface of the eye 10. The K1 to K4 values ​​can be determined by trial fitting using 3D images, OCT, or a test set, and interpreting the eye fit or edge lift using OCT or a slit lamp. The criteria for appropriate edge lift are well known to skilled scleral contact lens dispensers.

[0108] If there are multiple sets of base curves with sub-axes (e.g., myopia glasses for eliminating internal astigmatism), the calculation of the sag height is more complicated. The principle is the same for all the base curves with sub-axes and the zone widths that must be predetermined according to the requirements of the new shape of the cornea 12 to be shaped. Then, the sag height S of the glasses for all four sets of base curves with sub-axes 30 is determined. OZ1 、S OZ2 、S OZ3 、S OZ4 , and subtract these values ​​from the corresponding corneal sagittal heights S1, S2, S3, S4 of the above sub-axes to obtain the sagittal height S of the alignment area 26 az1 、S az2 、S az3 、S az4, and further converted into alignment curves AZ1, AZ2, AZ3, AZ4 for forming the alignment zone 26 of the P-Qdrt orthokeratology contact lens 20. It is important to match the sub-axis of the complex base curve with the sub-axis of the P-Qdrt alignment zone 26. Here, the complex base curve 30 of the central back surface of the myopic orthokeratology contact lens 20 is predetermined to eliminate internal astigmatism, while the P-Qdrt alignment zone 26 is set for directional control. The complex base curve 30 of the optical zone 22 is also flatter than the central corneal curvature, and its cylindrical axis is orthogonal to the cylindrical axis of the central cornea or tilted relative to the cylindrical axis of the central cornea. If the sub-axis of the base curve of the optical zone 22 is orthogonal to the sub-axis of the alignment zone 26, the corresponding set of base curves with sub-axes has a sag value S OZ1 、S OZ2 、S OZ3 、S OZ4 It can be directly added to or subtracted from the corresponding set of corneal sagittal heights S1, S2, S3, and S4. OZ1 ~S OZ4 If the sub-axes of S1 to S4 are tilted relative to each other, for example, at an angle of 45°, the formula for calculating oblique astigmatism will be applied to convert the sag height S OZ1 、S OZ2 、S OZ3 、S OZ4 Matched to corresponding S1, S2, S3, S4 with sub-axes. The oblique astigmatism power (O) at the deviation angle X° and the toric power T (in diopters) can be estimated using Equation 2, O = T*SIN((X°)*PI() / 180)^2, and the oblique astigmatism power (P) at an angle orthogonal to the angle X° can be estimated using Equation 2, P = T*COS((X°)*PI() / 180)^2.

[0109] The estimated values ​​are not exact numbers, but they are close enough for eyeglass production. With the two oblique astigmatism values ​​O and P of the base curve, we can deduce the sag S of each sub-axis of the alignment zone 26. az1 、S az2 、S az3 、S az4, and continues to calculate the posterior profile of the alignment zone 26 for constructing the alignment zone 26 of the P-Qdrt orthokeratology contact lens 20 having a toric or quadrant base curve 30. The anterior peripheral curve of the anterior peripheral zone in the P-Qdrt hard contact lens 20 (including conventional RGP, orthokeratology, and scleral lenses) can be designed as a single spherical or aspheric curve that is rotationally uniform so that the edge thickness will be rotationally uneven (convex and concave) because its posterior surface, alignment zone 26, and peripheral zone 28 are uneven. More preferably, the anterior peripheral zone of the P-Qdrt hard contact lens 20 can be calculated to follow the shape of the posterior peripheral zone, alignment zone 26, and peripheral zone 28 to obtain a rotationally uniform edge thickness.

[0110] For P-Qdrt soft contact lenses, the corneal sagittal height of each sub-axis is derived to form a non-uniform lens axial thickness, wherein there are multiple sets of sub-axes at the peripheral portion of the contact lens. More specifically, the edge thickness of the peripheral region of the P-Qdrt soft contact lens should be rotationally non-uniform. Soft contact lens materials are flexible, so non-uniform edge thickness can be produced on either the front or back surface of the contact lens. Preferably, the posterior peripheral curve of the contact lens peripheral region is formed non-uniformly, while the anterior peripheral region is rotationally uniformly curvatured. az1 、S az2 、S az3 、S az4 The proper placement of the contact lens over the scleral portion of the eye 10 can be calculated in the same manner as for the P-Qdrt scleral contact lens 20 by estimating the elevation height difference using 3D mapping, OCT, or trial glasses. The elevation heights in the sub-axes can be individually adjusted within a range of 50-100 microns, which will be reflected in the edge thickness of the finished soft contact lens.

[0111] Convert the eyeglass sag to a P-Qdrt alignment curve . The 4 sets of glasses sag S derived for the alignment area 26 az1 、S az2 、S az3 、S az4 Can be converted into 4 sets of back curves within the sub-axis for the predetermined area width. If the 4 sets of peripheral alignment curves are respectively aligned with the derived sag S for the area width and sub-axis, az1 、S az2 、S az3 、S az4 If the curves are matched, the curves can be 4 sets of spherical curves, 4 sets of aspherical curves, or simply a mixture of spherical and aspherical curves. Using equation 4, "Converting the sag value to curvature", we can convert the sag value S az Converted to an annular alignment area 26 with an alignment curve by Equation 4, AC=SQRT(((S az 2+(D az / 2-D IZ / 2) 2 +D IZ *(D az / 2-D IZ / 2)) / 2) 2 / S az 2 +(D IZ / 2) 2 )), where "D az ” is the diameter of the alignment area 26, and “D IZ ” is the diameter of the middle region 24 of the contact lens 20. The sag S of the alignment region 26 az It can be used to derive a single annular region using the above formula, or the region can be divided into regions with a total sag equal to S az A plurality of annular alignment areas 26, wherein the formula e is used az =SQRT(R b 2 -R a 2 ) / (Zone a +Zone b ) derived from the value of e, multiple alignment regions 26 can also be fused to form an aspheric alignment region 26, where R a and R b They have zone widths Zone a and Zone b The curvature radius of the two alignment regions to be fused. The aspheric alignment region 26 thus formed will have a curvature radius R a 、Zone width a +Zone b ) and e value e az The four groups of alignment areas AC1, AC2, AC3, and AC4 of each sub-axis can be calculated from the sag value S using the above equation 4. az1 、S az2 、S az3 and S az4 Converted.

[0112] The need to connect multiple sets of alignment zone curves with sub-axes to obtain a smooth, but not flat, annular alignment curve for the back surface of the contact lens 20 is well known to those skilled in programming lathes to cut contact lenses. By the above method, we can derive multiple sets of eye sagitta S for the zone width D and predetermine the base curve 30 (OZ and base curve BC) of the central optical zone 22 for any purpose without having to conform to the central corneal shape; and calculate the sagitta S of the intermediate zone 24 for the type of contact lens 20. IZ In orthokeratology lenses, SIZ is not zero and is calculated to design the intermediate zone 24 connecting the optical zone 22 and the alignment zone 26. For P-Qdrt RGP, P-Qdrt scleral lenses and PQdrt soft contact lenses, the intermediate curve 24 may be missing and S IZ The value of is assigned to zero.

[0113] In addition, we need to determine the factor K for adjusting the peripheral alignment force exerted by the P-Qdrt contact lens on the peripheral portion of the ocular surface; then obtain multiple sets of eyeglass sags with sub-axes for the alignment region 26; and transform the multiple sets of eyeglass sags to form multiple sets of alignment curves for the P-Qdrt hard contact lens 20. The anterior peripheral curve of the anterior peripheral region in the hard contact lens 20 is preferably made to rotationally follow the posterior peripheral region so that the edge thickness will be rotationally uniform and more comfortable when the contact lens 20 is worn on the eye 10.

[0114] The elevation height of the sub-axes of the eye 10 measured for designing the alignment zone 26 of a P-Qdrt soft contact lens can be incorporated into either the posterior or anterior peripheral surface of the contact lens. If the anterior peripheral surface of the contact lens peripheral zone is made uneven to balance the sagittal differences between the sub-axes or quadrants, the posterior surface of the alignment zone 26 should be made rotationally flat; vice versa, if the posterior surface is made uneven, the anterior surface can be created rotationally flat, and in both cases, the curvature of the opposite surface should not be followed. Uneven lens sagittal height S az1 、S az2 、S az3 、S az4 The uneven edge thickness of the soft contact lens can be converted so that the thicker peripheral edge fits on the steeper or concave ocular surface portion and the thinner peripheral edge fits on the flatter or elevated ocular surface portion, so that when the peripheral area of ​​the contact lens is worn on the eye 10, the lens covers the uneven peripheral ocular surface and becomes a rotationally flat surface.

[0115] The front and back surfaces of P-Qdrt contact lensesThe front and back profiles of the P-Qdrt contact lenses of the present invention can be any conventional contact lens design, an aspheric contact lens, or more preferably, incorporating a dual geometry or reverse geometry design, which has been disclosed in U.S. Patents #6,652,095 and #7,070,275, #6,543,897, #6,997,553, #7,360,892, #8,500,273, #8,864,307, #8,950,895 for various purposes including, but not limited to, vision correction, corneal rehabilitation / reconstruction, myopia control, or orthokeratology corneal shaping. We can use the aforementioned formulas and methods to create the P-Qdrt glasses of the present invention to form an uneven peripheral back curve in a hard contact lens 20 or an uneven edge thickness in a soft contact lens so that the contact lens 20 and the peripheral area fit more closely on the peripheral portion of the ocular surface of the eye 10 for directional control, upright control and peripheral alignment, which can significantly improve comfort, visual clarity and orthokeratology results.

[0116] P-Qdrt hard corneal contact lens test group For optimal directional control and peripheral alignment, the ECP may have a trial set for adjusting the rotational deviation of P-Qdrt contact lenses, such as those requiring directional control of the anterior or posterior toric optical zone 22 in the corneal RGP or orthokeratology contact lens 20. The trial set should have a predetermined P-Qdrt posterior profile for directional control and / or peripheral alignment suitable for the general population, and a drill point or line marking at 6 o'clock or any other fixed sub-axis for orientation identification. The rotation of the drill point or line marking on the trial lens can be observed to estimate the angle of deviation from the original setting when the trial lens is worn on the eye 10, and the axis and / or power of astigmatism can be adjusted to be ground on the anterior or posterior surface of the central portion of the contact lens 20. While the power and axis of astigmatism applied to the central portion of the anterior or posterior surface of a hard contact lens 20 can be calculated empirically, it is more reliable to perform an over-refract on the trial lens on the eye 10 and adjust the cylindrical axis for any rotational deviation. For ECPs who do not have a P-Qdrt trial set, they can empirically order a P-Qdrt corneal contact lens 20 that has a drill dot or line mark on the front surface for identification and to fine-tune the cylindrical axis and / or power during the warranty period. The trial set for testing orientation works best if the lens completely (100%) matches the corneal sagittal height of the sub-axis, while a partial (30%-90%) match will help adjust the rotational deviation to produce a central front or back toric contact lens 20.

[0117] For a corneal rigid lens set, the most useful range of sagittal differences between sub-axes will be between 120 and 250 microns. The larger the lens size, the higher the sagittal difference required for the test set. In one preferred embodiment, the sagittal difference of a 10.8mm P-Qdrt corneal refractive therapy lens is approximately 150 microns between two mirrored sub-axes (such as 0° vs. 180° or 90° vs. 270°), which is a "tilt set". There is another preferred embodiment for a 10.8mm P-Qdrt corneal rigid lens set that has a sagittal difference of approximately 150 microns between two orthogonal meridians (such as 0°-180° vs. 90°-270°), which is a "dual-axis set". Both the tilted and dual-axis sets can be marked with a drill dot or line mark at 6 o'clock or any sub-axis known to the ECP for identification of rotation.

[0118] The following two examples of the P-Qdrts corneal hard contact lens 20 of the present invention are for a "biaxial" group and a "tilted" group, respectively.

[0119] An example diagram of the sag of the P-Qdrt trial glasses with sub-axes is shown in Figure 3 :

[0120] Biaxial 10.8mm corneal contact lens (Biaxial #3)

[0121] Height (μ) / sub-axis BFS 0° 90° 180° 270° Arrow height (μ) 2007 1984 2027 1984 2027 Elevation to BFS(μ) 0 +23 -54 +23 -54

[0122] Tilt 10.8mm corneal contact lens (Tilt #3)

[0123] Height (μ) / sub-axis BFS 0° 90° 180° 270° Arrow height (μ) 2007 1984 2007 2027 2007 Elevation to BFS(μ) 0 +23 0 -54 0

[0124] P-Qdrt scleral glasses test group

[0125] RGP glasses can be divided into corneal glasses, corneoscleral glasses and (full) scleral glasses according to the size of the glasses, which are 8.0-12.5mm; 12.5-15.0mm and 15.0-25.0mm respectively. Glasses can also be classified according to the fitting zone, which are: all fitted on the cornea; fitted on the cornea and sclera; or all fitted on the sclera. We prefer that the definition of the fitting zone is used for the P-Qdrt scleral glasses 20 of the present invention. Therefore, if the cornea is very small and a 13mm glass is enough to cover the cornea and fit only on the sclera, it is a scleral glass. Scleral glasses are generally used to treat conditions with irregular corneas, such as keratoconus, peripheral marginal degeneration (PMD) or corneal trauma. Although the cornea is irregular, the scleral part is usually not too irregular, so rotationally symmetrical spherical or aspherical designs are usually acceptable for glasses sizes less than 15.0mm. If the glasses size is greater than 15.0 mm, the scleral profile may become a complex surface regardless of whether the cornea 12 is normal. If the wearer's upper eyelid is tight, the scleral glasses may be compressed by the upper eyelid to fit more closely on the upper eye surface of the eye 10 and form an uneven tear layer, which is thinner at the top and gradually thickens to the lower corneal edge. The uneven tear layer may then lead to residual astigmatism, which is usually against the rule (ATR) and unbearable. For some eccentric keratoconus or PMD cases, the asymmetry may extend beyond the corneal edge to the sclera part, thereby significantly affecting the centering and / or tilt of the glasses, which may then lead to oblique astigmatism. For those cases with a conjunctival macular protrusion on or beyond the corneal edge, it is necessary to design P-Qdrt glasses that relax the peripheral area 28 in one or two quadrants to adapt to the protrusion without excessive pressure. ECPs can use the P-Qdrt scleral spectacle test set to evaluate and demonstrate benefits in terms of improved spectacle centration, reduced residual or induced astigmatism, relief of conjunctival extrusion and / or vascular blanching, and patient comfort and clarity of vision when replacing spherical-aspheric spectacle lenses with P-Qdrt spectacles.

[0126] For 15.0-16.0mm scleral lens sets, the most useful sagittal difference between sub-axes will range from 50 microns to 300 microns. The larger the lens size, the higher the sagittal difference required for the test set. One preferred embodiment is that the sagittal difference of the 15.5mm P-Qdrt scleral lens set is approximately 100-120 microns at both ends of the meridian, which is the "tilt set". There is another preferred embodiment for the 15.5mm P-Qdrt scleral lens set, which has a sagittal difference of approximately 100-120 microns between two orthogonal meridians, which is the "bi-axis set". Both the tilted and bi-axis sets can be marked with a drill point or line mark at the 6 o'clock position or any sub-axis known to the ECP for identification of rotational deviation. For special clinics that need such a test set to test very irregular ocular surfaces, it is not limited to having a higher sagittal difference for sets with larger lens sizes, or to forming sets with any combination of lens sagittals in each sub-axis. The advantage of using such a set is that the fit can be viewed and assessed on most patients and fine-tuned more accurately before ordering glasses, saving chair time and reducing warranty replacements. Two P-Qdrts scleral contact lenses 20 of the present invention are illustrated here, one for the "dual-axis" set and the other for the "tilt" set.

[0127] An example diagram of the sag of the P-Qdrt trial glasses with sub-axes is shown in Figure 3 :

[0128] Biaxial 15.5mm scleral contact lens (#F with biaxial #2)

[0129] Height (μ) / sub-axis BFS 0° 90° 180° 270° Arrow height (μ) 4480 4425 4536 4425 4536 Elevation to BFS(μ) 0 +55 -54 +55 -54

[0130] Tilt 15.5mm scleral contact lens (#F, tilt #2)

[0131] Height (μ) / sub-axis BFS 0° 90° 180° 270° Arrow height (μ) 4480 4425 4480 4536 4480 Elevation to BFS(μ) 0 +55 0 -54 0

[0132] Software tool for calculating and ordering Q-Qdrt glasses According to the present invention, a computer software tool can also be implemented to help ECPs (eye care professionals) determine and use corneal information for multiple sets of alignment zone curves with sub-axes for P-Qdrt contact lenses 20. The software includes a database portion and a set of logical calculation components, such as Figure 8 and Figure 9 shown.

[0133] Figure 8A simplified processing flow according to the present invention is illustrated. In step 700, the eye sagitta and the sagitta differences of the sub-axes are determined using measured corneal or ocular surface information, which includes but is not limited to corneal curvature, e-value, elevation map, corneal size, topography or other data in OCT, refractive data, reference table or trial kit (step 720). Then, a best-fit prototype contact lens of known specifications is determined, which has a rotationally uniform sagitta for the BFS cornea or eye shape (step 710). After determining the corneal sagitta of the sub-axis, the software tool integrates the corneal or ocular surface information and calculates multiple sets of eye sagitta differences within the sub-axis, and then uses the obtained eye data to modify the alignment area sagitta of the prototype contact lens within each sub-axis and generate P-Qdrt lens specifications (step 730). The data input is performed by the client processor, for example Figure 9 The computing glasses specifications can be performed by the client processor or a server connected to the client processor through a global data communication network ( Figure 9 The manufacturing specifications are then transmitted to the manufacturer ( Figure 9 "Manufacturer A" or "Manufacturer B" in the ) or a predetermined manufacturing machine at the customer's site to manufacture P-Qdrt contact lenses based on the P-Qdrt lens specifications (step 740).

[0134] The present invention eyewear can be used to treat refractive errors or corneal diseases, such as myopia, hyperopia, presbyopia, or astigmatism as described herein. After the eyewear is designed to treat the indicated condition and centered on the user's eye (as described above), the treatment method of the present invention will include applying the eyewear to the user's eye to correct myopia, hyperopia, presbyopia, astigmatism, or other refractive errors or corneal diseases, and / or to achieve corneal reshaping through orthokeratology. Those skilled in the art will understand how to guide further use of the present invention eyewear based on the lens material (hard or soft contact lenses), treatment modality (standard or orthokeratology lenses), and other factors.

[0135] Example

[0136] Example 1

[0137] Patient 860908 was provided with a pair of P-Qdrt orthokeratology contact lenses with the following dimensions:

[0138] <Right Eye>

[0139] KM: 41.49D(8.13mm)@0°,44.49D(7.59mm)@90°

[0140] e value: E f :0.68 / E s :0.32

[0141] HVID: 12mm

[0142] Refraction :-5.00-3.00@180 (myopia -5.00D astigmatism 3.00D axis 180)

[0143] Elevation height of elevation map: (8mm area)

[0144] Elevation (μ) 0° 90° 180° 270° OD 17 -47 8 -63

[0145] Optical zone 22: width 5.6mm, curvature radius 9.66mm

[0146] Middle area 24_1: width 0.3mm, curvature radius 5.88mm

[0147] Middle area 24_2: width 0.3mm, curvature radius 6.47mm

[0148] Alignment area 26: width 1.8 mm,

[0149] The curvature radius of the best fitting sphere (BFS) is 8.06 mm

[0150] Sub-axis 0° 90° 180° 270° Curve (e = 0.48) mm 8.21 7.97 8.21 7.89

[0151] Peripheral area 28: width 0.4mm, curvature radius 11.30mm

[0152] Front optical zone 31 (power surface): zone width 7.0mm, curvature radius 9.3mm

[0153] Material refractive index: 1.4333

[0154] Center thickness (CT): 0.2mm

[0155] Front peripheral area: Follows the back curve with a 0.12mm edge thickness.

[0156] Sub-axis 0° 90° 180° 270° Curve (e=0) mm 8.0 7.84 8.0 7.79

[0157] Edge thickness: 0.12mm rotating

[0158] <Left Eye>

[0159] KM: 41.45D(8.14mm)@0°,44.31D(7.61mm)@90°

[0160] e value: E f :0.61 / E s :0.19

[0161] HVID: 12mm

[0162] Refraction :-4.75-3.00@180 (myopia -4.75D astigmatism 3.00D axis 180)

[0163] Elevation height of elevation map: (8mm area)

[0164] Elevation (μ) 0° 90° 180° 270° OS 15 -50 25 -60

[0165] Optical zone 22: width 5.6mm, curvature radius 9.60mm

[0166] Middle area 24_1: width 0.3mm, curvature radius 5.82mm

[0167] Middle area 24_2: width 0.3mm, curvature radius 6.41mm

[0168] Alignment area 26: width 1.8 mm

[0169] The curvature radius of the best fitting sphere (BFS) is 8.06 mm

[0170] Sub-axis 0° 90° 180° 270° Curve (e = 0.48) mm 8.26 7.93 8.26 7.85

[0171] Peripheral area 28: width 0.4mm, curvature radius 11.30mm

[0172] Front optical zone 31 (power surface): zone width 7.0mm, curvature radius 9.25mm Material refractive index: 1.4333

[0173] Center thickness (CT): 0.2mm

[0174] Front peripheral area: Follows the back curve with a 0.12mm edge thickness.

[0175] Sub-axis 0° 90° 180° 270° Curve (e=0) mm 8.04 7.83 8.04 7.78

[0176] Edge thickness: 0.12mm rotating

[0177] The patient wore the orthokeratology contact lenses for 7 nights, 7-8 hours per day. After this correction period, the patient experienced a reduction in myopia and astigmatism to zero degrees, with a distance visual acuity of 20 / 20 in both eyes. This equated to a reduction of -6.25D of myopia and 3D of astigmatism in the right eye, and a reduction of -6.00D of myopia and 3D of astigmatism in the left eye. The maintenance period (almost zero degrees) continued during all waking hours, with nighttime wear maintained for 5-7 hours. The topography of the cornea was well centered and had a uniform central ablation as a 4mm treatment area with a very steep peripheral ring to support effective reduction of myopia and high astigmatism. The case was followed up for over 1 year, and the patient was satisfied with his vision, comfortable, and had no side effects.

Claims

1. A contact lens, comprising: an optical zone (22) located at a centrally located portion of the contact lens, the optical zone (22) extending radially outward from the center of the contact lens, the optical zone having an anterior surface, a posterior surface, and a base curve (30), wherein the posterior surface of the optical zone has a rotationally symmetric curvature; and an annular alignment zone (26) surrounding the optic zone and extending radially outward from the optic zone, the alignment zone having an anterior surface and a posterior surface and providing directional control of the contact lens, wherein the contact lens is bisected by at least a first axis and a second axis, and wherein each axis comprises two opposing radial lines extending from an intersection of the first axis and the second axis, thereby forming: (i) a first sub-axis (51), the first sub-axis (51) having a first alignment curve and a first predetermined sag in the alignment region; (ii) a second sub-axis (52), the second sub-axis (52) having a second alignment curve and a second predetermined sag in the alignment region; (iii) a third sub-axis (53), the third sub-axis (53) having a third alignment curve and a third predetermined sag in the alignment region; and (iv) a fourth sub-axis (54), said fourth sub-axis (54) having a fourth alignment curve and a fourth predetermined sag in said alignment region, wherein the predetermined sag of one of the sub-axes in the alignment region is different from the predetermined sag of at least one other sub-axis in the alignment region, and wherein each sub-axis is orthogonal to an adjacent sub-axis, and the predetermined sags of three of the sub-axes in the alignment region are different from each other.

2. The contact lens according to claim 1, wherein The contact lens also includes an intermediate zone (24) coupled to the optic zone (22) and extending radially outward from the optic zone (22).

3. The contact lens according to claim 2, wherein The optical zone further includes an inner gradient optical zone (23) located in a central portion of the optical zone (22), and wherein the inner gradient optical zone (23) has a single set of curvatures that is steeper than the base curve (30).

4. The contact lens according to claim 2, wherein the contact lens is used for myopic orthokeratology, The base curve (30) is rotationally unitary and has a radius that is longer than the measured central corneal curvature.

5. The contact lens according to claim 4, which is used for myopic kinematics with internal astigmatism, wherein The base curve (30) is toric.

6. The contact lens according to claim 2, wherein the contact lens is used for orthokeratology for hyperopic vision, The base curve (30) is rotationally monocurvature and has a radius shorter than the measured central corneal curvature.

7. The contact lens according to claim 3, wherein the contact lens is used for orthokeratology for myopia and presbyopia, The base curve (30) is rotationally unitary and has a radius that is longer than the measured central corneal curvature.

8. The contact lens according to claim 3, wherein the contact lens is used for orthokeratology for hyperopia and presbyopia, The base curve (30) is rotationally monocurvature and has a radius shorter than the measured central corneal curvature.

9. The contact lens according to claim 1, wherein The curvature of the front surface is one of a spherical, aspheric, or toric curvature.

10. The contact lens of claim 1, further comprising a peripheral region (28) having an anterior surface and a posterior surface, the peripheral region coupled to the alignment region (26) and extending radially outward from the alignment region (26).

11. The contact lens according to claim 10, wherein The rear surface of the peripheral region (28) has a rotationally uniform curvature but is less flat in shape than the alignment region.

12. The contact lens according to claim 11, wherein The front surface of the peripheral region is parallel to the uneven shape of the rear surface of the peripheral region (28) so as to form a rotationally uniform edge thickness.

13. The contact lens according to claim 11, wherein The front surface of the peripheral region is rotationally symmetric in curvature, thereby forming an uneven edge thickness that is relatively thicker in one or more portions of the peripheral region and relatively thinner in other portions of the peripheral region.

14. The contact lens according to claim 13, wherein The contact lenses are hard contact lenses.

15. The contact lens according to claim 14, wherein The contact lenses are soft contact lenses.

16. The contact lens according to claim 1, wherein The predetermined sags in the alignment region of all of the sub-axes are different from each other.

17. A method of manufacturing the contact lens according to claim 1, the method determining data for orientation control, upright control, or peripheral alignment of the contact lens using a computer, the method comprising the steps of: Manufacturing data is determined by inputting data representing at least one of the following into the computer, the computer being configured to calculate the data: Corneal sagittal height reading; Corneal shape factor, p-value, e-value or q-value; Keratometric reading (KM); Corneal size; specifications of the selected best-fitting prototype contact lens; Refractive errors to be corrected or shaped; and ocular surface information obtained through OCT, 3D images, or trial wear groups; generating data by the computer based on at least one of the above input data; generating manufacturing specifications by the computer based on the predetermined process; transmitting the manufacturing specifications to a predetermined manufacturing machine; A contact lens or a set of contact lenses is manufactured by the manufacturing machine.

18. The method according to claim 17, wherein The inputting step is performed by a client processor, and the calculating step is performed by the client processor or by a server connected to the client processor via a global data communication network.

19. Use of the contact lens according to any one of claims 1 to 16 in treating refractive error or corneal disease, wherein the refractive error or corneal disease is myopia, hyperopia, presbyopia or astigmatism.

Images