Eyeglass manufacturing method using variable index layer

IS 2 286 296 T3

DESCRIPTION

Eyepiece manufacturing method using variable index layer and a lens.

Field of the invention

The present invention generally relates to a method of manufacturing eyepieces using a layer with a variable index of refraction. More specifically, the present invention pertains to patient-specific eyeglass lenses made with a variable index aberration device to more precisely correct lower order aberrations and further correct higher order aberrations. The present invention also provides a means of correcting vision problems caused by retinal dysfunction.

Background of the invention

Present manufacturing techniques for spectacle lenses are capable of producing lenses that correct only the lowest order aberrations (sphere and cylinder). Typically, lens blanks are available in differentiated refractive power steps of 0.25 diopters. In most cases, these steps are too extensive to create optimal vision for a patient's eye.

Conventional lenses can also be formed by laminating two lenses or lens blanks to form a composite lens, as described in US 4,969,729 A and US 4,883,548 A, US 4,969,729 A discloses a composite plastic lens, which is composed of one lens. front plastic and a rear plastic lens, each lens having a corrective characteristic. The lenses are attached to one another using an adhesive layer that has a refractive index. index equal to the refractive index of the front and rear lenses when cured. US 4,883,548 A discloses a process for creating a laminated ophthalmic lens, which is composed of a first and a second lens element. The first and second lens elements each have specific lens optical values ​​and are held in storage for assembly into a composite ophthalmic lens. After a first and a second lens element are selected, the surfaces of both lens elements are coated with an adhesive and the surfaces are laminated, forming a single lens. However, like individual lenses, composite lenses correct only lower order aberrations and the constituent lens elements of composite lenses are typically available only in discrete steps.

Current manufacturing techniques do not effectively treat vision problems resulting from retinal dysfunction. For example, in macular degeneration, patients with vision loss in selective areas of the fundus normally close near the center of vision. Laser treatment of the affected areas further destroys retinal tissue, causing blindness in the treated areas. Clinical studies have shown that the human eye and brain are capable of switching to other areas of the retina to replace the damaged area with an undamaged area. In other words, damaged areas in the retina are essentially bypassed by the brain. Ultimately, vision loss will occur when part of an image falls on the damaged retina. Consequently, there is a need to fabricate an eyepiece such that the image can be "warped" around the dysfunctional tissue to allow the entire image to focus on the healthy tissue that remains. US-A-5,777,719 deals with the resolution of retinal images.

In view of the problems mentioned above, the need for an optical element that generates a single wavefront phase profile becomes apparent. Traditional manufacturing methods create such profiles by grinding and polishing, such that the manufacturing method is very expensive due to the amount of time and expertise required. Summary of the present invention

The present invention uses the technology developed by the wavefront aberration device, in which a layer of variable index material, such as a curable epoxy, can be sandwiched between two flat or curved plastic or glass plates. This intercalation is then exposed to curing radiation (ie, UVA light) which is spatially or temporally modulated to create spatially resolved refractive index variations. This will allow the fabrication of a lens that is capable of introducing or compensating for high and low order aberrations. The invention relates to an eyepiece lens and to a method for manufacturing a lens according to claims 1 and 4.

Most simply, two lens blanks are laminated together with an epoxy layer such that the lenses used in conjunction approximately correct the patient's refracting spherical and cylindrical correction to within 0.25 diopters.

Subsequently, the epoxy aberration device would be exposed to curing radiation in a pre-programmed manner to match the refractive properties of the spectacle lens to the exact spherical and cylindrical prescription of the patient's eye.

Another application of the present invention is to manufacture progressive addition or multifocal lenses constructed of a layer of variable index material sandwiched between the two lens blanks. The drawback with progressive addition lenses today is that, like normal spectacle lenses, a true fit for a patient's eye cannot be achieved due to current manufacturing techniques. Using the two lenses and epoxy, a progressive addition lens or tailored reading lens can be fabricated by properly scheduling the cure of the epoxy aberration device.

The present invention provides an opportunity to make lenses that give patients "supervision." To achieve supervision, higher order aberrations in the patient's eye must be corrected. Since these higher order aberrations, unlike spherical and cylindrical refractive error, are highly asymmetric, the centering of the optical axis of the eye with the higher order correction zone ("monitoring zone") is important. To minimize this effect, one could devise a spectacle lens that incorporates a monitoring zone only along the central optical axis, allowing the patient to achieve monitoring for one or more differentiated viewing angles. The rest of the lenses would then be cured to correct only the lower order aberrations. An optional transition zone could be created between the monitoring zone and the normal vision zone allowing a gradual reduction of higher order aberrations. Again, all of this would be achieved by programming resolved es2

ES 2 286 296 T3 partially of the curing of the epoxy aberration device.

To cover a larger field of view with supervision, a multitude of supervision “islands” could be created. The supervisory islands are then connected by transition zones that are programmed to gradually shift higher order aberrations to create smooth transitions.

In bifocal lenses, the refractive power in differentiated steps of 1 diopter is added in the lower area of ​​the lenses to help the spectacle wearer in near distance vision, that is, reading. For cosmetic reasons, the visible dividing line between the distance vision area and the reading area is unpleasant for many presbyopia patients. With the fact of progressive addition lenses, the sharp dividing line between the distance area and the reading area has been eliminated by introducing a continuous varifocal corridor of vision with a refractive power that slowly changes from the distance vision prescription to the reading prescription.

However, due to manufacturing limitations there are several disadvantages with progressive addition lenses. First, vision through areas outside the corridor is perceptibly distorted, making progressive addition lenses unsuitable for many patients. Second, while the individual patient's prescription is applied to the distance viewing area, the added refractive power for the reading area is offered only in discrete steps of 1 diopter. Third, the distance between the distance vision centers and the reading vision areas is set by the lens design and cannot be changed to suit an individual's preference or application. Additionally, the hallway layout is fixed for any particular brand of lens and cannot be changed based on the patient's actual viewing preferences or the selected spectacle frame.

Therefore, when prescribing a progressive addition lens, the eye care professional has to choose from an assortment of lens designs and manufacturers that most closely matches the requirements of the patient. The present invention enables one to manufacture a lens that is fully tailored and optimized for individual patient requirements.

Finally, the present invention can be used to "warp" the retinal image, such that damaged portions of the retina will be bypassed by the image. To do this, the patient's visual field needs to be traced with a perimeter or microperimeter. From this healthy retina mapping, the spectacle lenses could be manufactured using the epoxy aberration device.

Description of the drawings

The new features of this invention, as well as the invention itself, both in terms of its structure and its operation, will be best understood from the attached drawings, taken in conjunction with the attached description, in which the characters of reference refer to similar parts, and in which:

Figure 1 is a perspective view of an eyepiece incorporating a monitoring zone for long distance applications;

Figure 2 shows a cross-sectional view of Figure 1;

Figure 3 shows a top view of a progressive addition lens, which includes a monitoring zone and reading zone;

Figure 4 shows a top view of a reading or special application lens;

Figure 5A shows a top view of a lens that includes a multitude of monitoring islands, which cover a larger view with monitoring;

Figure 5B shows a top view of a multifocal lens including a multitude of reading islands, allowing distance vision correction and simultaneous reading correction;

Figure 6 shows a text object reflected on a damaged retina;

Figure 7 shows the image of the same object as Figure 6 from the patient's perspective;

Figure 8 shows the patient's view of the image after the brain closes the damaged retina;

Figure 9 shows an image focused on a damaged retina, with a corrective lens in place;

Figure 10 shows the image as the patient initially sees it;

Figure 11 shows the image as the patient sees it after the brain closes the damaged retina; Y

Figure 12 shows a manufacturing sequence of the present invention.

Detailed description of a preferred embodiment

Referring initially to Figure 1, a lens assembly incorporating a monitoring zone is shown and is generally designated 100. Figure 1 shows that lens assembly 100 includes a top lens 102, an index layer variable 103, and a lower lens 104. In a preferred embodiment, the variable index layer is made of ultraviolet curing epoxy, which exhibits a refractive index that can be changed by exposure to ultraviolet radiation. However, it should be noted that other materials exhibiting similar characteristics, namely a variable refractive index, can be incorporated into the present invention.

Variable index layer 103 composes normal vision zone 106, transition zone 110, and monitoring zone 108, where the epoxy in each zone is cured to a specific refractive index. The normal viewing zone 106 corrects for lower order spherical and cylindrical aberrations of the patient's eye. The transition zone 110 allows a gradual reduction of higher order aberrations. The monitoring zone 108 lies along the optical axis of the patient (not shown) and corrects for higher order aberrations, allowing the patient to achieve monitoring for one or more discrete viewing angles. It is intended that the shape of the lens 100 be exemplary of the shape of a typical eyepiece lens, and that any shape, including highly curved lenses, can be used as long as it does not depart from the present invention.

Referring now to FIG. 2, a cross section of lens 100 is depicted such that upper lens 102 has thickness 112, epoxy layer 103 has thickness 116, and lower lens 104 has thickness 114. Epoxy layer 103 is sandwiched between upper lens 102 and lower lens 104 and is held in place by retainer 118.

IS 2 286 296 T3

Description of alternative embodiments

Referring now to Figure 3, an alternate embodiment of the present invention is illustrated as a progressive addition lens and is generally designated 200. Figure 3 shows a top view of a transition lens 200 in which There is a monitoring zone 202, a transition zone 204, and a short distance vision zone 206. The normal viewing area 208 of the progressive addition lens 200 is corrected for lower aberrations. Again, the creation of the various viewing zones is sandwiched by selective curing of the epoxy aberration device between two glass (or plastic) blanks, not by traditional means of grinding or molding these characteristics into a blank. Transition lens 200 has a similar cross section to that illustrated in Figure 2.

Referring now to Figure 4, another alternative embodiment of the present invention is illustrated as a reading lens and is generally designated 300. Figure 4 shows a top view of a reading lens 300 in which there is a monitoring zone 302, a transition zone 304, and a normal vision zone 306. The reading lens 300 has a cross section similar to that shown in FIG. 2. Supervisory zone 302 can be used for, but not limited to, high resolution applications such as reading, precision closing work, etc.

Referring now to Figure 5A, an alternate embodiment of the present invention is illustrated as a monitoring lens that covers a larger field of view and is generally designated 400. Figure 5A shows a top view of a lens supervision 400 in which there are a plurality of supervision islands 402, and a transition zone 404. The plurality of monitoring islands 402 create a greater field of view for the patient, while the transition zone 404 is manufactured to gradually change higher order aberrations to create smooth transitions.

Referring now to Figure 5B, another alternate embodiment of the present invention is illustrated as a multifocal lens that allows simultaneous correction for distance vision and reading vision and is generally designated 450. Figure 5B shows a top view of a multifocal lens 450 in which there are a plurality of optical islands 452, each representing the patient's reading prescription, while the background area 454 represents the patient's far vision prescription, or vice versa. Ideally, the diameter of the optical islands is on the order of 100 microns, so that a maximum number of optical islands falls within the typical pupil size of 2 to 6 mm. diameter.

A special application of this invention is the use to correct vision problems caused by retinal dysfunction, for example, by eye diseases such as glaucoma or macular degeneration. Figure 6 shows an eye generally designated 500, in which an image 502 is reflected by the cornea of ​​the eye and the lens 504 onto the inner surface of the eye 500 where the retinal tissue 506 is damaged. The patient initially sees only a portion of the image and an obstruction, as shown in figure 7. Finally, the brain disconnects the damaged part of the retina and the patient's vision no longer includes the obstruction, such a vision is represented in Figure 8. Although the patient no longer sees an obstruction, a part of the image remains unseen. The present invention is capable of correcting this phenomenon as illustrated in Figures 911. Figure 9 again shows an eye generally designated 600, in which an object 602 is reflected through the cornea of ​​the eye and lens 604 onto the inner surface of eye 600 where retinal tissue 606 is damaged. However, a lens 608 made using the epoxy wavefront aberration device is positioned in front of the eye 600. The retinal image 609 of the object 602 is warped around the damaged retinal tissue 606, such that nothing is lost from the image 602. Figure 10 shows the image that the patient sees. As previously mentioned, over time the brain will terminate the signals generated by the damaged retinal tissue 606 and the patient will see the entire image 602 as shown in Figure 11.

Figure 12 shows a flow chart in which the manufacturing steps of the present invention are set forth and designated generally 700. First, the patient's eye must be reflected to determine the wavefront prescription. Second, both the upper and lower lenses must be selected. This selection corrects for both spherical and cylindrical aberrations of the patient to within 0.25 diopters. Next, one side of the first lens is epoxy coated. The second lens is then placed on the epoxy-coated surface of the first lens, such that the epoxy is interposed between the two lenses. Finally, the epoxy is cured to conform to the wavefront prescription.

While the various embodiments of the present invention as shown herein and set forth in detail may well achieve the objectives and provide the advantages set forth hereinbefore, it is to be understood that it is merely illustrative of a preferred embodiment and a preferred embodiment. alternative of the invention, and which is not intended to be limited to the details of construction or design shown herein, other than those described in the appended claims. The appended claims contain reference signs for certain claim elements for the sole purpose of making the claims easier to understand. Such reference signs are not intended to limit the scope of the object protected by the claims in any way.