MXPA97005978A - Non-corrective lenses descentrated for anteo - Google Patents

Abstract

The present invention relates to spectacle lenses, for use in non-corrective lenses of dual lenses, in combination with a frame for supporting lenses in the normal line of sight of a user, comprising: A lens body; a front and a posterior lens body, which defines the thickness of the lenses (between them), the front surface is substantially conformed to a portion of the surface of a first sphere that has a first center, the rear surface conforms substantially a portion of the surface of a second sphere having a second center, said first center and said second center are offset from each other to progressively decrease said thickness of the lens, wherein said lens is mounted on the frame, such that a central optical line drawn through said first and second center is spaced from and substantially parallel to the normal line of sight of the user, in each of the horizontal planes and a vertical plane

Description

NON-CORRECTIVE LENSES DESCENTRATED FOR GOGGLES The present invention relates in general to lenses used in glasses, and more particularly to uncorrected non-corrective lenses to reduce optical distortion.

Antecedents of the Invention In recent years, a great variety of improvements have been made in the field of eyeglasses, especially in relation to glasses that are intended to be used in active sports or as fashionable eyeglasses. These improvements have been incorporated into eyeglasses that have unit lenses, such as the "Blades®" design (Oakley, Inc.) the "M Frame®" line (Oakley, Inc.), and the "Zero®" line also produced by Oakley , Inc. This eyeglass design has a wide variety of functional advantages, such as maximizing the peripheral light interception, reducing optical distortion and increasing the level of comfort of the wearer, compared to the previous active sports eyeglasses. .

The unitary lens of the "Blades®" goggles incorporates a cylindrical geometry that is shown, for example, in U.S. Patent No. 4,859,048, issued to Jannard. This geometry allows the lens to adjust very much to the face of the wearer and intercept light, wind, dust, etc., so that they do not attack the spectator's wearer (front address), or the periphery ( lateral direction). See also US Patent No. 4,867,550 extended to Jannard (toroidal lens geometry).

Although the previous unit lens systems provided a complete field of view from side to side and good lateral protection to the eye, optical distortion still existed in power. For example, in a unit lens system the angle of incidence from the eye of the wearer to the rear surface of the lens changes as the visual angle of the wearer rotates towards the lateral direction. This results in an uneven refraction between the light that enters closer to the front of the lens, and the peripheral light entering through the lateral ends. To correct this source of prismatic distortion, U.S. Patent No. 4,859,048 shows the taper of the lens thickness from the middle portion to the side edge.

In the lenses of prior inventions, double lens systems have also been employed in which two separate lenses are mounted along a front frame. In the previous systems of glasses with double lens, both the right and the left lens were more or less co-planar in their final configuration. In this way, the visual angle of the wearer, when looking at it from the front, generally intersected with the rear surface of the lens perpendicular to the surface of the lens in the optical zone. One of the disadvantages of this lens configuration was that the glasses basically did not offer any lateral protection to the eye unless special modifications were made, such as vertically elongated temples or lateral eye covers.

The dual lens systems were then created, in which the lateral edge of each lens curved back from the frontal plane, and around the wearer's head, to provide a curvature similar to that achieved by the unit lens systems of the lens. high curvature Although double lens lenses with a fairly high curvature provided lateral protection to the eye, the curvature of the lens generally introduced a measurable prismatic distortion through the angular field of view of the wearer. This was particularly pronounced in lenses that contained materials with a low refractive index. In addition, although it is sometimes advisable to have high base curves (eg base 6 or higher) to optimize protection while maintaining a low profile, such lenses have not been practical in the past due to the relatively high level of prismatic distortion. In this way, there remains a need for non-prescribed high-base lenses, for use in double-lens lenses that can intercept light essentially across the entire angular field of view and at the same time minimize optical distortion throughout that field.

Summary of the Invention According to one aspect of the present invention, a spectacle lens is provided for use in uncorrectable double lens lenses. The eyeglass lens is used in combination with a frame to hold the lens in the path of the normal visual angle of the wearer.

The lens consists of a lens body, which has a front surface, a back surface and a certain thickness between them.

The front surface of the lens fits a portion of the surface of a solid geometric shape. Preferably, the front surface of the lens substantially fits a portion of the surface of a first sphere having a first center. The back surface of the lens substantially fits a portion of the surface of a solid geometric shape, which may be the same as that which conforms to the front surface or may be different. Preferably, the rear surface substantially fits a portion of the surface of a second sphere having a second center.

The first center and the second center are offset from one another in order to taper the thickness of the lens. The lens is mounted on the frame so that a line drawn through the first center and the second is generally maintained in parallel with the normal visual angle of the carrier.

The lens can be cut from a lens blank, or directly conformed to its final configuration by injection molding or other techniques known in the industry. Preferably, the lens is oriented on the head of the wearer by means of the frame of the eyeglasses, so that the normal visual angle of the wearer traverses the anterior surface of the lens at an angle greater than about 95 °, and preferably within the range from about 100 ° to about 120 °, while maintaining the optical axis of the lens in a generally parallel relationship with the normal visual angle of the wearer. The optical axis of the lens may or may not pass through the lens.

Methods for making the lens of the present invention are also shown.

With the detailed description of the preferred embodiments set out below, other features and advantages of the present invention will be obvious when taken together with the appended claims and drawings.

Brief Description of the Drawings Figure 1 is a perspective view of glasses incorporating corrected tapered lenses made in accordance with an embodiment of the present invention.

Figure 2 is a cross-sectional view taken along lines 2-2 of Figure 1.

Figure 3 is a cross-sectional schematic horizontal view of a non-tapered lens of a prior invention for a dual lens goggle system.

Figure 4 is a horizontal cross-section schematic view of a tapered lens for a dual lens goggle system.

Figure 5 is a cross-sectional view like that of Figure 2, showing corrected tapered lenses having a greater base curvature, according to another embodiment of the present invention.

Figure 6 is a perspective view of a lens blank that fits a portion of the surface of a sphere, in which a profile of the lens to be cut out of the blank is shown according to a preferred embodiment of the present invention. invention.

Figure 7 is a sectional perspective view of the hollow lens blank with spherical shape, with a tapered wall, and the lens of Figure 6.

Figure 8 is a cross-sectional horizontal view of a lens constructed in accordance with a preferred embodiment of the present invention.

Figure 9 is a plan view from the top of the lens of Figure 8, showing a high curvature in relation to a carrier.

Figure 10 is a cross-sectional and elevational view of the right side of the lens and of the carrier of Figure 9, in which the angle of inclination of the lens is shown.

Figure 11 schematically illustrates the projection of the lens profile from a desired orientation within a spectacle frame to the lens blank, in accordance with a preferred embodiment of the present invention.

Figure 12 is a front elevational view of the lens and the lens blank of Figure 6, rotated to project the mechanical axis of the blank perpendicular to the page.

Detailed Description of the Preferred Embodiments Although the preferred embodiments will be discussed below with reference to lenses having a "spherical" front and back surfaces (surfaces that conform substantially to a portion of the surface of a sphere), those of ordinary skill in the art will understand that The invention can also be applied to lenses having a different surface geometry. Furthermore, it will be understood that the present invention has application for lenses of many shapes and frontal orientations, apart from the definitive position illustrated in this document.

With reference to Figures 1 and 2, there are illustrated glasses 10, such as sunglasses, having a first lens and a second lens 12, 14, constructed in accordance with an embodiment of the present invention. Although the invention is illustrated in the context of a spectacle design that Oakley markets under the name of Eye Jackets ™, the present invention only relates to the curvature, taper and orientation of the lens at the wearer's head. Accordingly, the particular lens shape shown in Figure 1 is not essential to the invention. Moreover, lenses of many other shapes and configurations incorporating the present invention can be constructed, as will be obvious from the disclosure made in this document.

Similarly, the frame 16 shown is not essential to the present invention. The frame 16 can limit only the bottom edge or edges of the lenses 12-14, only the top edges, or the entire lenses as illustrated. Alternatively, the frame 16 can serve as a limit to any other portions of the lens, which will be apparent to those of skill in the art. Unframed eyeglasses may also be constructed in accordance with the present invention, as long as the orientation of the lenses on the wearer's head is substantially maintained at a predetermined ratio to the normal visual angle as discussed below. However, preferably the lenses 12, 14 are each mounted in an annular orbit as shown.

A pair of lugs 20, 22 are pivotally attached to the frame 16. Alternatively, the lugs 20, 22 may be attached directly to the lenses 12, 14. The frame may be fabricated from a wide variety of metals, or compounds of relatively rigid molded thermoplastic materials that are well known in the art, and can be transparent or of any variety of colors. The techniques of construction with injection molding, machining or others, are well known in this industry.

The lenses according to the present invention can be manufactured by a variety of processes well known in the art.

Generally high-quality optical lenses are cut from preformed injection molded primordia. Since the right and left lenses should preferably be mirror images, one with respect to the other, usually only the right lens will be discussed in this document. Alternatively, the lens can be molded directly to obtain its definitive shape and size, thus eliminating the need to carry out other cutting steps after molding.

Preferably, the lens or primer from which the lens is cut is injection molded and consists of a relatively rigid and optically acceptable material, such as a polycarbonate. Other polymeric materials can also be used to make the lenses, such as the CR-39 and various high refractive index plastics known in the art. The off-center tapered correction of the present invention can also be applied to glass lenses, although the need for correction in the present context is generally more pronounced in non-glass materials.

If the lens is to be cut from a blank, the taper and the curvature of a carefully preselected portion of the molded blank is transferred to the lens according to a preferred manufacturing process described below. Preferably, the frame has a slot or other connecting structure that cooperates with the molded curvature of the lens to minimize a deviation from the curvature as it was molded and even improve the retention thereof.

Alternatively, the lens or blank can be stamped or cut from a generally flat and tapered sheet material and then bent to achieve a curved configuration in accordance with the present invention. Then, this curved configuration can be maintained by using a curved frame of relative rigidity, or by applying heat to the curved blade so that it retains its curved configuration, as is well known in the thermoforming art.

Even more preferably, the curvature of both lens surfaces is created in the process of molding and polishing the blank, and the shape of the lens is cut off from the blank according to the invention, as described below.

With reference to Figure 2, the lens 14 of the present invention is characterized in a horizontal plane by having a generally arcuate shape, extending from a middle edge 24 to at least a portion of the wearer's field of view, and preferably, almost the entire field of view thereof, up to a side edge 26. The length of the lens arch, from the middle edge 24 to the side edge 26 in a double lens system, will generally be within the range of approximately 1 1 / 2 to about 3 1/2, and preferably within a range of about 2 to about 3. In a preferred embodiment, the arc length of the lens is about 2 3/8.

Although the outer surfaces of the lenses 12-14 are illustrated as falling in a common circle 31, the right and left lenses will generally be inclined, such that the middle edge of each lens will fall out of the circle 31, and the side edges will they fall inside the circle 31. Such tilting of the lenses increases the angle? (Figure 2) and makes the optical correction achieved by the present invention more advisable.

When worn, the lens 14 should extend at least through the normal visual angle 27 of the wearer, and preferably substantially through the peripheral vision zones of the wearer. As used herein, the term "normal visual angle" of the carrier will refer to a line projecting straight from the eye of the wearer, with almost no angular deviation either in the vertical or horizontal plane, as illustrated by FIG. line 130 of Figures 9 and 10.

The lens 14 has a front surface 28, a rear surface 30 and a variable thickness therebetween. The thickness of the lens 14 in the region of the middle edge 24, when dealing with polycarbonate lenses, is generally within the range of about 1 mm to about 2.5 mm, and preferably within the range of about 1.5 mm to about 1.8. mm. In a preferred embodiment, the thicker portion of the lens 14 is on or near the optical axis, and is approximately 1.65 mm.

Preferably, the thickness of the lens 14 is tapering smoothly, but not necessarily linearly, from the maximum thickness near the middle edge 24 to a relatively smaller thickness at the side edge 26. The thickness of the lens near the side edge 26 it is generally within the range of approximately 0.635 mm approximately 1.52 mm, and, preferably within the range of approximately 0.762 mm to 1.27 mm. In a preferred polycarbonate embodiment, the lens has a minimum thickness in its median zone of approximately 1.15 mm. The minimum thickness at the side edge 26 is generally governed by the impact resistance that the lens is desired to have.

Figure 3 illustrates schematically the refraction in a lens 41 of a previous invention with horizontal cross sections of inner and outer circular surfaces, with a uniform thickness 44. With such a lens 41, the angle of incidence of the rays from the lens 41 to eye 46, it changes through the entire angular field of view. For example, a beam to which we will refer for descriptive purposes as an average ray of light 50, affects the lens 41 at an angle a in the perpendicular of the point of incidence. As is well known in this art, the refraction of light on the transmitting surfaces depends, in part, on the angle of incidence of the light rays. The ray 50 is refracted in opposite directions, both on the outer surface 52 and on the inner surface 54 of the lens 41, resulting in a transmitted beam 56 parallel to the incident ray 50. The transmitted beam 50 is displaced laterally, with respect to to the path of the incident ray 50, for a distance 58. This displacement represents a first-order source of optical distortion.

In addition, the refractory displacement is even more pronounced at the lateral end 60 because there is a greater angle of incidence β. A peripheral incident ray 62 experiences a greater displacement 64 than the average incident ray 50, according to the Snell Laws, as can be understood by those who have ordinary knowledge of optical science. The discrepancy between the displacement of the peripheral ray 64 and the displacement of the median ray 58 results in a second-order optical distortion. This second order distortion can cause a substantial curvature of an image seen through relatively lateral portions of the lens 41.

Figure 4 schematically illustrates a lens 71 of tapered thickness. To compensate for the greater angle of incidence at the lateral ends 60 of the lens 41 (Figure 3), as described in the context of the unit lens systems in U.S. Patent No. 4,859048, issued to Jannard. The taper produces a thickness 74 of the minor lens at the lateral end 76, relative to a thickness 78 of the lens at a point 80, which is more toward the middle. This smaller thickness 74 reduces a certain amount of displacement of the peripheral rays 82, relative to the displacement of the peripheral rays 64 through the non-tapered lens 41 of Figure 4. In other words, the smaller thickness 74 of the lens near the lateral end 76 of the tapered lens 71 compensates to some extent for the existence of a greater angle of incidence ß ', relative to the thickness 78 and to the angle of incidence a' at the point 80 which is more towards the middle.

The resulting difference between the displacement of the peripheral beam 82 and the displacement of the middle ray 84 in the same lens 71 is not as great as the corresponding difference in Figure 3, whereby the second-order optical distortion is reduced. It should be noted that the degree of correction of the second order distortion depends on the relationship between the manner and degree of taper of the vertex 85 with each side end 76 and the manner in which the angle of incidence changes over the same distance. .

The lens 17 of Figure 4 is illustrated as being mounted within a frame (not shown) so that the normal visual angle 86 of the carrier passes perpendicularly through the lens 71 at the apex of the lens or mechanical axis 85. In other words, the angle of incidence to the perpendicular of the lens is zero for the normal visual angle of the wearer. The outer and inner surface of the lens 71 in the transverse illustration are adjusted to compensate for circles of equal radius represented by center points 87 and 88 respectively. A line drawn through the central points 87 and 88, which in this document will be referred to as the optical axis of the lens, is collinear with the normal visual angle in the definitive orientation with the glasses on. For ease of description, this conventional configuration will be defined as a centrally oriented lens. Circumferentially in a clockwise or counter-clockwise direction of the normal visual angle 86, the angle of incidence to the perpendicular of the lens increases regularly from zero at the apex of the lens 85. It could be advisable a greater degree of curvature for aesthetic reasons, so that the eyes are protected laterally from airborne garbage, or to intercept the peripheral light. The curvature can be achieved by using closed horizontal (high base) curved lenses, such as small radius spherical lenses, or by mounting each lens in a position that is lateral and then inclined relative to centrally oriented double lenses. Such inclination displaces the normal visual angle 86 of the existing collinear relationship with the optical axis, and changes the optics of the lens. As a result, double lens lenses of previous inventions with quite a "curve" around the sides of the wearer's face, generally have some degree of prismatic distortion.

In accordance with the present invention, an improved optical configuration and a method for minimizing prismatic distortion are provided. Although the present invention can be applied to a wide variety of shapes and orientations of lenses, the invention has a special utility for dual lenses having a wide base curvature and showing a high degree of curvature in their definitive orientation once placed on the face.

With reference to Figures 2 and 5, the illustrated glasses incorporate slanted lenses 12 and 14 or 102 and 104, mounted in a laterally rotated position relative to conventional double lens mounts that are centrally oriented. An inclined lens can be conceived with one orientation, relative to the wearer's head, which can be achieved by starting with conventional double-lens lenses having centrally oriented lenses, and curving the frame inward at the temples so that it fits curved to the sides of the head.

As a consequence of a greater curvature, the normal visual angle 27 of the carrier no longer incurs perpendicularly to the lens 14, as illustrated in Figure 4. Instead, the angle of incidence? ° for the visual angle of the carrier 27 is generally greater than 90 °, and to achieve a good curvature it should be greater than about 95 °, and preferably should fluctuate between 100 ° and about 135 °, and in an embodiment with a base of 9.5 it will be about 101.75 °. Will lenses with a lower base usually have an angle? greater in its definitive orientation once placed, and the angle? in an embodiment with a base of 6.5 it will be approximately 113.4 °. In a base embodiment 4 having a pupillary distance of 2.8 inches, the angle? It will be approximately 1 19,864 °.

Figure 5 illustrates the horizontal cross section of eyeglasses 100 according to one embodiment of the present invention, similar in style to that illustrated in Figure 2, except that it has lenses 102 and 104 with a more closed curvature (higher base), as well as a curvature on the sides of the head possibly greater. When the eyeglasses 100 are worn, a side edge 106 of the lens 104 curves quite around the wearer's temple and is very close thereto, so as to provide good lateral protection to the eye, as has been discussed.

An anterior (front) lens surface 108 of the present invention will generally conform to a portion of the surface of a regular geometric solid, such as a sphere 110, which is shown in this document in horizontal cross section. Accordingly, the front surfaces of the spherical lenses 102 and 104 of the illustrated embodiment can be characterized by a radius.

By industry agreement, the curvature can also be expressed in terms of a base value, such that the radius (R) in millimeters of the front surface of the lens equals 530 divided by the base curve, or 530 R = B (1 ) The present invention offers the ability to construct double lens goggle systems with a relatively high curvature by using lens primers with a base of 6 or greater, preferably between about 7-1 / 2 and 10-1 / 2, and preferably between about 8 and 9-1 / 2, and, in one embodiment, between about 8-3 / 4 and 9. For example, the radius of the circle that fits the anterior surface of a lens with a base of 8- 3/4 will be approximately 60.57 millimeters. As a comparison, the radius of the circle that characterizes the anterior surface of a 3-base lens will be approximately 176.66 millimeters.

The embodiment of the present invention illustrated in Figure 5 can be cut from an 8-3 / 4 base lens primer having a thickness of approximately 0.0649 inches on the optical axis and around 0.053 inches as a reference at a point of two inches. along the outer circumference of the lens from the optical axis. Alternatively, the lens can be molded directly to the final shape and configuration it would have.

Figure 6 is a perspective view of a blank 122 whose convex outer surface 136 generally conforms to a portion of the surface of a three-dimensional geometric shape 124. Those of skill in this art will understand that the lens according to the present invention can be made in any variety of geometric shapes.

Preferably, the outer surface of the lens will conform to a shape having a continuous smooth surface with a constant horizontal radius (sphere or cylinder) or a progressive curve (ellipsoid, toroidal or ovoid) in any of the horizontal or vertical planes. However, the geometric shape 124 of the embodiments described herein is usually spheroid.

The sphere 124 illustrated in Figures 6 and 7 is an imaginary three-dimensional solid, and a portion of the wall thereof is suitable for cutting a lens 20. As is known in the art, in order to accurately cut lenses it is often necessary to produce lens primordia 122 of which will be obtained, by cutting a 120 lens. However, it should be clear to those who are aware of this technique, with respect to the illustrations in Figures 6 and 7, that the use of a separate primordium is optionally and that the lens 120 can acquire its definite shape and configuration by shaping it directly if desired.

It can also be seen in Figures 6 and 7 that the lens 120 and / or the blank 122 can be placed in a great variety of locations along the sphere 124. For purposes of the present invention, the optical axis 132 serves as the line of reference for the orientation of the lens 120 relative to the sphere 124. In the illustrated embodiment, in which both the outer surface and the inner surface conform to a portion of a sphere, the optical axis is defined as the line 132 joining the the two centers C1 and C2. For the effects of non-spherical lens geometry, the analogue reference line can be shaped differently than the connection of the two geometric centers of the spheres, as will be obvious for those who have knowledge of the technique.

Finally the lens 120 is formed in such a way that it retains the geometry of a portion of the wall of the sphere as illustrated in Figure 7. The location of the lens 120 in the sphere 124 is selected such that when the lens 120 is oriented on the frame of the glasses, the normal visual angle 130 of the carrier, through the lens, will generally remain parallel to the optical axis 132 of the geometric configuration from which the lens 120 was obtained. Figures 6 and 7, the lens 120 is a right lens having a high degree of curvature, as well as a certain angle of inclination. A lens with a different shape, or with a lower degree of curvature, can be superimposed on the optical axis 132 of the imaginary sphere 124 from which the lens was formed. However, the fact that the optical axis of the imaginary sphere 124 passes through the lens 120 or not is not important, as long as the visual angle 130 of the lens 120 is maintained generally in parallel in the definitive orientation with the glasses posts, with the optical axis 132.

For purposes of the present invention, the term "substantially parallel" means that the visual angle 130, when the lens 120 is oriented in the position in which it is definitively placed, generally does not deviate within the horizontal plane by more than about ± 15 °. of its parallelism with optical axis 132. Preferably, the normal visual angle 130 should not deviate more than about ± 10 ° from the optical axis 132, and, more preferably, the normal visual angle 130 should not deviate further from ± 5 °, approximately, and, preferably, no more than ± 2 °, approximately, of its parallelism with the optical axis 132. Ideally, the visual angle 130 is parallel to the optical axis when it is in its definitive orientation. Generally, a spectacle frame has a vertical plane of symmetry that is substantially parallel to the visual angle 130. Accordingly, the optical axis 132 will be substantially parallel to the plane of vertical symmetry of the frame.

When there are variations of the parallelism in the horizontal plane, these generally have a greater negative impact on the lens than the variations of parallelism existing in the vertical plane. Consequently, the polyhedron angle existing between the visual angle 130 and the optical axis 132 in the vertical plane, may exceed the limits set forth above, for some glasses, as long as the horizontal element of the angle of deviation is within the parameters of deviation mentioned above in relation to its orientation in parallel. Preferably, the visual angle 130 does not deviate in the vertical plane by more than ± 10 ° approximately, and preferably by no more than ± 3 ° approximately from the optical axis in its definitive orientation.

Figure 7 is a sectional view of the lens 120, the blank 122 and the geometric shape 124 of Figure 6. This view shows that the preferred geometric shape 124 is hollow and its walls have a variable thickness, as indicated by horizontal cross section 134 on the optical axis of the geometric shape 124.

The tapered walls of the preferred geometric shape 124 are the result of two horizontally decentered spheres, represented by their center points C1 and C2 and their radii R1 and R2. An outer surface 136 of the preferred lens blank 122 is fitted to a sphere (of radius R1), while an inner surface 138 of the blank 122 is fitted to the other dial (of radius R2). By adjusting the parameters that describe the two spheres, you can also adjust the taper type of the primordium 122.

In particular, the parameters of the two spheres to which the outer surface 136 of the blank and the inner surface 138 fit are preferably chosen so as to produce zero refractive power, or non-prescribed lenses. When CT represents a selected central thickness (maximum thickness of the wall of the hollow geometric shape 124), n constitutes a refractive index of the primordium material, R1 is regulated by the design chosen for the curvature of the outer surface 136 and R2 is You can determine according to the following equation: CT R2 = R1-CT + n (1) CT / n represents the separation of the spherical centers C1 and C2. For example, when it is desired to have a base 6 lens because it has been selected for design reasons, it is decided that the thickness of the center is 3 mm, and the refractive index of the preferred material (polycarbonate) is 1586, then R2 it can be determined as follows: 530 3 R2 = 6 -3 + 1,586 = 87,225 (2) For this example, the radius R1 of the outer surface 136 is equal to 88.333 mm, the radius R2 of the inner surface 138 is equal to 87.225 mm, and the spherical centers C1 and C2 are separated by 1892 mm. These parameters describe the curvature of the blank 122 of the preferred embodiment.

In the case of the preferred embodiment, the optical axis 132 is the line that passes through both center points C1 and C2 of the off-center spheres. The line passes through the thickest portion of the walls 124 of the preferred geometric shape on an optical axis 140, although it may not be true when it comes to non-spherical embodiments. The optical axis 140 passes through the surface 136 of the illustrated blank 122, although this is not necessary. The optical axis 140 does not fall into the lens 120, although it can happen in larger lenses or in lenses that try to have less curvature once placed.

Figure 8 illustrates a horizontal cross-section of the preferred lens 120, in which the geometric shape 124 to which the outer surface 136 and the inner surface 138 fit are shown translucently. The blank 122 is omitted in this drawing. According to the present invention, the optical axis 132 related to the selected taper is aligned to be in parallel with the normal visual angle 130 of the carrier when the lens 120 is to be mounted in a spectacle frame.

In addition, although preferred embodiments are circular in both horizontal and vertical cross section, a variety of lens configurations are also possible in both planes, in conjunction with the present invention. Thus, for example, the outer surface of the lens of the present invention can be generally adjusted to a spherical shape as shown in Figures 6 and 7. Alternatively, the lens can be adjusted to a circular cylinder shape straight, frustoconical, elliptical cylinder, ellipsoid or ellipsoid of revolution, or any number of other three-dimensional shapes. However, regardless of the particular vertical or horizontal curvature of the outer surface, the inner surface should be chosen so that the thickness of the lens is gently smoothed at least as far as the horizontal plane is concerned.

Figures 9-12 will help to describe the method for choosing a location in the blank 122 from which the right lens 120 is cut, according to a preferred embodiment of the present invention. It will be understood that a similar method can be used to construct the left lens as it is the dual lens goggles of the preferred embodiment.

As a first step, a desired general curvature for the outer surface of the lens 136 can be chosen. For the preferred lens 120, this selection determines the base value of the blank 122. As noted elsewhere in this document, together with the present invention, various other curvatures can be used. You can also pre-select the thickness of the lens. In particular, the minimum thickness can be selected such that the lens supports a previously selected impact force.

You can also choose the desired shape of the lens. For example, Figure 12 illustrates an example of a front elevation view of the lens 120. Generally the particular shape that is chosen is not important for the optics of the off-center lens described herein.

It is also possible to choose the orientation in which the glasses are to be placed once they are placed, relative to the normal visual angle 130 of the carrier 126. As mentioned above, the preferred orientations can provide a pronounced lateral curvature to obtain lateral protection and for Intercept the peripheral light, and also for aesthetic reasons. For example, the embodiment illustrated in Figures 6-12 employs an inclined lens 120 to achieve curvature. Alternatively, the curvature can be achieved by the use of higher base lenses and a more conventional orientation (not inclined) Figures 9 and 10 illustrate more simply how the orientations can be related to the visual angle 130 of the carrier .

The designer of the glasses can also choose a certain degree of angle of inclination, or vertical inclination, as can be deduced from Figure 10, in which the vertical orientation of the lens 120 relative to the head of the carrier 126 is illustrated schematically. , and in relation, in particular, to the normal visual angle 130. As illustrated, it is desirable to have a downward inclination angle due to various reasons, among which a better fit to the anatomy of any head is included. As will be obvious to those skilled in the art, a lens 120 having a central mechanical point that falls below the horizontal plane intersecting the optical axis 132 (see Figure 7) will tend to have a downward inclination angle as illustrated in Figure 10. This is because the lens 120 has been formed below the equator of the sphere relative to the optical axis. Since the orientation of the lens 120 relative to the optical axis 122 of the imaginary sphere should be the same as the orientation existing between the lens 120 and should be parallel to the normal visual angle 130 once the glasses are put on, any lens that is cut off from this sphere below the optical axis 132 it must have some degree of downward inclination.

Referring now to Figure 11, a framing of the horizontal orientation of the lens 120 in the blank 122 is shown. The normal viewing angle 130, with respect to which the selected orientation is measured, remains substantially parallel to the optical axis 132.

Once the aesthetic design has been determined as illustrated in the Figure 11, and that the shaped blank 122 has a suitable base curvature to fit the aesthetic design, the aesthetic design can be "projected" onto the surface of the sphere to thereby reveal the portion of the sphere that is suitable for use as a lens 120. The projection of the lens shape on the sphere should move around the surface of the sphere until it is positioned in such a way that the lens cut of the sphere at that location shows the proper curvature and an appropriate angle of inclination. to the aesthetic design without rotating the lens 120 out of the orientation in which the optical axis of the sphere of the sphere is generally parallel to the normal visual angle of the final orientation in which the lenses will remain once placed.

Although not illustrated in this document, it will be understood that a similar projection can be made with respect to the selected vertical orientation, as illustrated, for example, in Figure 10. Figure 10 provides reference points in the edge shape. upper 152 of the lens and at the lower edge 152 relative to the visual angle 130. Next, the projection may be moved up or down until the upper edge 152 and the lower edge are aligned simultaneously with corresponding points on the outer surface 136 of the blank, while maintaining the visual angle 130 substantially parallel to the optical axis 132.

The projection, both of the horizontal profile and the vertical profile, can be performed simultaneously, locating a unique position of the blank 122 corresponding to the desired three-dimensional shape of the lens (including the front elevation form shown in Figure 12), in which the visual angle 130 is parallel to the optical axis 132 or to another reference line of the blank 122. Of course it should be understood that the lines 130 and 132 may be almost parallel; that is, they fall within the acceptable range of angular deviation discussed above.

Then, this shape can be cut out of the blank 122 or directly shaped with the final configuration that the lens will have. The resulting lens 120 not only conforms to the desired shape, but also minimizes prismatic distortion.

Figure 12 illustrates a blank 122, such as the one shown, that fits a portion of the surface of the sphere of Figures 6 and 7. In Figure 12, the blank 122 has been rotated in such a way that the The mechanical center of the primordium is illustrated in the center of the drawing. The illustrated lens 120 has a middle edge 148, a side edge 144, an upper edge 152 and a lower edge 154. At least a portion of the right lens 120 falls in the lower quadrant (the third) which is on the left side of the blank 122. Preferably, in one embodiment of the invention in which both the curvature and the downward inclination angle are shown, at least about half the area of the lens will fall within the third quadrant of the blank 122. Preferably, all the area of the lens 120, or almost all of it, will fall below and to the left of the optical axis as illustrated. Lenses having a similar angle of inclination, but less curvature, can be placed in the blank 122 so that at least 50% or more of the lens area is within the lower right quadrant (the second) of the blank 122.

In this way, the present invention offers a precise method to provide a correct correspondence between the taper and the angle of incidence angle, from the eye of the wearer to the surface of a lens. By recognizing a new relationship between the visual angle of the carrier and the tapering shape, the present invention allows the use of any variety of lens designs, while minimizing prismatic distortion. For example, the designer may choose a desirable orientation and curvature for the lens in relation to the visual angle of the wearer. The orientation and curvature can be selected from a wide range of tilt angles (ie vertical "tilt" of the lens), horizontal tilt, base value and proximity to the face of the wearer, including those parameters that result in a high degree of curvature. The shape of the taper can then be chosen, by the method of the present invention, in such a way that the prismatic distortion is minimized.

Although the above invention has been described in terms of certain preferred embodiments, there will be other embodiments that are obvious to those of ordinary skill in the art in view of what is described herein. Accordingly, it is not intended that the present invention be limited by the description of the preferred embodiments, but it is intended that it be defined only with reference to the claims set forth below.

Claims (2)

Having described the invention, it is considered a novelty and therefore the content is claimed in the following: CLAIMS

1. - A lens for glasses to be used in glasses with non-corrective double lens, in combination with a frame that holds the lenses in the normal visual angle of the wearer, which consists of the following: a lens body; a front surface and a back surface on the lens body, which defines the thickness of the lens therebetween; the front surface substantially adjusts to a portion of the surface of a first sphere having a first center; the back surface substantially adjusts to a portion of the surface of a second sphere having a second center; said first center and said second center are offset from each other, in order to taper said lens thickness; wherein said lens is mounted on the frame in such a way that a line drawn through said first center and said second center is maintained generally in parallel with the normal visual angle of the carrier.

2. - A lens as in claim 1, wherein said first sphere has a greater curvature than a base 6, approximately. A lens as claimed in Claim 2, wherein said first sphere has a greater curvature than a base 8, approximately. A lens as claimed in Claim 3, wherein said sphere has a curvature with a base of about 8.75, and said lens has a maximum thickness of about 1.65 mm, and a minimum thickness of about 1.15 mm. A method for manufacturing dual-lens glasses that provide an intersection of the peripheral light, such glasses being adapted so that a right lens and a left lens are placed through the normal visual angle of the wearer, and the method is constituted by the following steps : cutting a right lens of a first primer lens having a first optical axis; cutting a left lens of a second lens blank having a second optical axis; Y mount the right lens and the left lens so that the first optical axis and the second optical axis are substantially parallel in relation to the normal visual angle. A method for manufacturing a lens for double lens lenses, and the method consists of the following steps: select the desired shape of the lens; select the desired curvature and angle of inclination for the lens according to its orientation once placed; projecting the desired shape into a tapered lens blank; Cut the lens so that it fits the desired shape; Y mounting the lens in the goggles so that the optical axis of the lens is maintained substantially parallel to the plane of symmetry of the goggles.