CN113253481B - Spectacle lens with invisible microstructure - Google Patents

Abstract

The present invention discloses an ophthalmic lens with a contact microstructure, having an object-side surface and an eye-side surface, comprising a first refractive region, having a first refractive power based on correcting the refractive error of the eye; and a second refractive power a region having a different refractive power from the first refractive power and having a function of imaging an object on a position other than the retina of the eye to suppress the development of ametropia of the eye, characterized in that the second refractive region It is composed of multiple circular sub-regions distributed on the surface of the eye side. The diameter of each sub-region is 2mm-6mm. Each sub-region has multiple annular etching grooves. The width of the etching groove is 30-100mm. Micron, the distribution and depth of the etched grooves enable the sub-region to form a micro-lens structure and provide the second refractive power. The present invention can suppress the development of myopia while not affecting the aesthetics of spectacle lenses.

Description

A spectacle lens with invisible microstructure

technical field

The invention relates to an ophthalmic lens, in particular to an ophthalmic lens with microstructure, especially an ophthalmic lens with invisible microstructure.

Background technique

The human eye plays a vital role in obtaining human information. According to statistics, more than 80% of human information acquisition comes from the eyes. At present, social life is full of various electronic screens, which emit light of different intensities, and the human eye is used more and more every day, resulting in continuous refractive error of the human eye, and this refractive error Growth is not accelerating. According to incomplete statistics, more than 80% of college students have refractive errors of more than 200 degrees.

On the basis of refractive correction, there have been functional spectacle lenses that can suppress the refractive error of the human eye. For example, a concentric Fresnel multi-focal lens is set, and multiple refractive regions are concentrically configured in the lens. This lens has the function of focusing the image on the retina of the glasses. If the patient uses a lens for inhibiting myopia to view objects, then The image of the object is formed on the retina, and the image is formed at the point in front of the retina at the same time, so it can obtain the effect of inhibiting the development of myopia through the two-layer image in the visual process.

Chinese invention patent CN 104678572 B discloses an ophthalmic lens, in which a number of circular small area mirrors with a diameter of about 0.8 mm to 2 mm are arranged in different areas to form a second refractive area. The progression of myopia is suppressed by the image obtained in front of the retina by the second refractive area while visually recognizing the image of the object formed by the first refractive power. Meanwhile, the second refraction area is not formed in a circular area with a radius of 2.5 mm to 10.0 mm centering on the optical center of the spectacle lens in order to maintain sufficient visibility and obtain a good wearing feeling. In the above solutions, it can be seen from the embodiments that the circular small-area mirrors for forming the second refractive area are arranged on the object-side surface of the spectacle lens.

For spectacle lenses, as shown in FIG. 1 , there is an object-side surface 1 and an eye-side surface 2 . In actual preparation, the eye-side surface 2 is a fixed spherical, aspheric or astigmatic surface, and the object-side surface 1 is processed into, for example, a spherical, aspherical or progressive surface, and the small-area mirror in document CN 104678572 B is also arranged on the object side on surface 1. As a result, there will be many small protrusions or depressions on the surface of the spectacle lens to form the second refraction area, which will cause major defects in the aesthetics of the spectacle lens and affect the visual perception. At the same time, when the object-side surface 1 is a progressive surface, the difficulty of designing and manufacturing the small-area mirror will also increase, so this structural design is not suitable for progressive ophthalmic lenses.

Contents of the invention

The object of the present invention is to provide a spectacle lens with invisible microstructure, which can ensure sufficient visibility and good wearing feeling while suppressing the continuous increase of the refractive error of the eyes, and ensure the aesthetic appearance of the spectacle lens, and Can be applied to progressive glasses.

In order to achieve the purpose of the above invention, the technical solution adopted by the present invention is: a spectacle lens with invisible microstructure, which has an object-side surface and an eye-side surface, which includes a first refractive area, and has a refractive error based on correcting the eye. and a second refractive area having a refractive power different from said first refractive power and having a function of imaging an object on a position other than the retina of the eye to suppress the development of refractive error of the eye, so The second refraction area is composed of multiple circular sub-areas distributed on the side surface of the eye, each sub-area has a diameter of 2 mm to 6 mm, and each sub-area has a plurality of annular etched grooves, and the etched grooves The width is 30-100 microns, and the distribution and depth of the etched grooves enable the sub-region to form a micro-lens structure and provide the second refractive power.

In the above technical solution, by engraving the annular groove, due to interference imaging, it is equivalent to having a second focal plane on both sides of the main focal plane. The distance between the front and back focal planes is equal to the main focal plane, and the energy of the front and back focal planes is the same, thereby realizing the suppression of the development of refractive error. The width of the etched groove is 30-100 microns, invisible to the naked eye, and has the function of aesthetics and the function of microlens.

In the above technical solution, the structure of the sub-region is determined by the following steps:

(1) According to the refractive index n of the lens, the front and rear surface curvature radii r ₁ , r ₂ , the main focal length F, and the focal plane distance d, calculate the equivalent curvature radius r of the secondary area, where the main focal length F corresponds to the first refractive area The focal length of the main focal plane, the focal plane distance d is the distance between the main focal plane and the secondary focal plane corresponding to the second refraction area;

(2) According to the diameter of the sub-region and the equivalent radius of curvature r, divide the annulus of the sub-region, the method is:

a. First use the Fresnel-like zone plate method on the surface where the sub-region is located, and divide according to the phase change of 2π or π to obtain 3 to 5 annular zones;

b. If the phase division unit is 2π, it is necessary to change π for binarization, the setting greater than π is the base surface, and the area smaller than π is etched to remove the π phase depth; if the phase division unit is π, it is necessary to change π/2 is used for binarization, and the area greater than π/2 is set as the base plane, and the area smaller than π/2 is etched out of the π/2 phase depth;

c. Adjust the etching width, so that the width of the etching groove is 30-100 microns, and complete the division of the ring zone of the sub-region.

In the above technical solution, within the distribution range of the sub-areas, the first refraction area and the second refraction area form a mixed area, wherein the area of the second refraction area formed by the sub-areas is the total area of the mixed area 20% to 60% of that.

In a preferred technical solution, the area of the second refraction area formed by the sub-areas is 30% to 40% of the total area of the mixed area.

In a preferred technical solution, the sub-regions are evenly distributed in the mixing region.

In a preferred technical solution, the eye-side surface is a spherical surface, and the object-side surface is a spherical, aspherical or progressive surface.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

1. In the present invention, the sub-region used to form the second refractive region is set on the surface of the eye, so that a spherical surface can be selected for the surface of the eye, which is convenient for design and processing, and does not affect the shape design of the surface of the object, so that it can be applied In applications such as progressive ophthalmic lenses;

2. The present invention forms an equivalent microlens structure through annular grooves. The width of the grooves does not exceed 100 microns, which is difficult to distinguish with the naked eye. While suppressing the development of myopia, it does not affect the aesthetics of spectacle lenses.

Description of drawings

Fig. 1 is the structural representation of spectacle lens;

Fig. 2 is the optical path schematic diagram of embodiment;

Fig. 3 is a schematic diagram of the design process of the sub-region in the embodiment;

Fig. 4 is a schematic diagram of the design process of the sub-region in another embodiment.

Among them: 1. Object side surface; 2. Eye side surface.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

Embodiment 1: An ophthalmic lens with invisible microstructure, as shown in FIG. 1 , has an object-side surface 1 and an eye-side surface 2 . For the eye-side surface 2, after the traditional spherical surface processing, an annular groove is engraved on the spherical surface. After engraving the groove, due to interference imaging, it is equivalent to having a second focal plane on both sides of the focal plane. The front and rear focal planes are the same distance from the main focal plane, and the energy of the front and rear focal planes is the same.

Referring to Fig. 2, the main lens is the main lens of the lens, and its focal length is set as F; the microlens is the secondary lens, and its focal length is set as f, and the distance between the secondary focal plane and the main focal plane is d. Knowing the main focal length F and the focal plane difference d, the secondary focal length can be calculated.

The focal length of the lens is determined by the curvature radii r ₁ and r ₂ of the two surfaces of the lens, the thickness and the refractive index n. The thickness of the glasses is very small, it can be considered that the distance between the lenses is close to 0, and the focal length of the lenses can be written as

According to r ₁ , r ₂ , and d, the refractive index of the lens can calculate the radius of curvature r of the equivalent microlens in the sub-region. Its calculation steps are:

A. First calculate the focal length F of the main lens according to r ₁ , r ₂ , n;

B. Calculate the focal length f of the secondary lens according to the focal lengths F and d of the primary lens;

C. According to r ₁ , the focal length f of the secondary mirror, and the refractive index n, calculate the radius of curvature r of the second surface of the secondary mirror.

In this way, the radius of curvature r of the secondary mirror is obtained.

example 1:

n=1.597 (nominal refractive index 1.6), myopia 300 degrees. The radius of curvature of the first surface is 392.76mm, the radius of curvature of the second surface is 131.2mm, and the center thickness is 1.2. Then it can be obtained that the main focal length of the lens is 330mm, if the focal plane needs to be advanced by 10mm, the secondary focal length is 320mm, and the calculated secondary radius of curvature is 128.5mm. If the focal plane needs to be advanced by 20mm, the calculated secondary curvature radius is 125.8mm.

Example 2:

n=1.499 (nominal refractive index 1.49), myopia is 400 degrees. The radius of curvature of the first surface is 457.8mm, the radius of curvature of the second surface is 98mm, and the center thickness is 1.2mm. The calculated focal length of the lens is 249.9mm. If the focal plane needs to be 10mm backward, the radius of curvature is 104.07mm. If the focal plane needs to be shifted back by 40mm, the calculated radius of curvature is 109.9mm. If it needs to be moved back by 100mm, the calculated secondary radius of curvature is 126.4mm.

Example 3:

n=1.499 (nominal refractive index 1.49), myopia is 400 degrees. The radius of curvature of the first surface is 457.8mm, the radius of curvature of the second surface is 98mm, and the center thickness is 1.2. It can be obtained that the focal length of the lens is 249.9mm. If the focal plane needs to be advanced by 40mm, then the secondary focal length is 209.9mm, and the calculated secondary radius of curvature is 85.24mm.

After obtaining the radius of curvature of the sub-region, divide the annulus of the sub-region and set the width of the groove to determine the structure of the sub-region.

the way is:

A. First divide according to the phase change of 2π (2pi), this step is the same as the Fresnel zone plate.

B. If there are too few circles to change the 2π phase division, it can be divided based on π. Generally speaking, at least 3 to 5 rings are needed to form interference imaging.

C. If the phase division unit is 2π, it is necessary to change π for binarization, the setting greater than π is the base plane, and the area smaller than π is etched to remove the π phase depth. If the phase division unit is π, it is necessary to change π/2 for binarization, the setting greater than π/2 is the base plane, and the area smaller than π/2 is etched to remove the π/2 phase depth.

D. According to the above steps, the result is similar to 50% duty cycle. According to the definition of diffractive optics, the duty cycle only changes the diffraction efficiency and does not change the phase, that is, adjusting the duty cycle does not affect the focal length, but only affects the energy. Here, the etching width is adjusted so that the etching width is between 30 and 100 microns (here, the entire surface needs to be calculated, so that the widths of all rings are uniform to facilitate fabrication). The line width of more than 100 microns can be easily obtained by human eyes, and there is no invisible effect.

Referring to accompanying drawing 3, it is the process of setting the annulus and groove width of the spectacle lens described in Example 3 using the above method.

In Example 3, the calculated secondary curvature radius is 85.24mm. The phase changes by 2π, and the thickness d=0.55um/(1.499-1)=1.1um. That is to say, when the thickness difference is 1.1 microns, it needs to be divided into one circle. Assuming that the diameter of the circle is 3mm, then the difference in sagittal height is 1.7 microns. Considering the change of 1.1 microns by 2π, it needs to be divided more finely, that is, 0.55 microns is divided into one circle, that is, the entire 3mm diameter can be divided into 1.7/0.55=3 circles . At this time, the interference diffraction conditions can be satisfied.

Accompanying drawing 4 is the schematic diagram of setting process of another embodiment. The calculated secondary curvature radius is 65.24mm. The phase changes by 2π, and the thickness d=0.55um/(1.499-1)=1.1um. That is to say, when the thickness difference is 1.1 microns, it needs to be divided into one circle. Assuming that the diameter of the circle is 3mm, then the difference in sagittal height is 4.2 microns. Considering that 0.55 microns is divided into one circle, that is, the entire 3mm diameter can be divided into 4.2/0.55=7 circles.

Claims (5)

1. An ophthalmic lens having a contact microstructure, having an object-side surface and an eye-side surface, comprising a first refractive area having a first refractive power based on a refractive error of the corrected eye; and a second dioptric region having a refractive power different from the first refractive power and having a function of imaging an object on a position other than a retina of the eye to suppress development of ametropia of the eye, characterized in that: the second refraction area is formed by a plurality of circular sub-areas distributed on the surface of the eye side, the diameter of each sub-area is 2-6 mm, each sub-area is provided with a plurality of annular etching grooves, the width of each etching groove is 30-100 micrometers, and the distribution and the depth of the etching grooves enable the sub-areas to form a micro-lens structure and provide second refractive power;

the structure of the secondary region is determined by the following steps:

(1) According to the refractive index n of the lens, the radius of curvature r of the front and back surfaces ₁ 、r ₂ Calculating to obtain an equivalent curvature radius r of a secondary region, wherein the primary focal length F is the focal length of a primary focal surface corresponding to the first refraction region, and the focal surface distance d is the distance between the primary focal surface and the secondary focal surface corresponding to the second refraction region;

(2) Dividing the zone of the secondary region according to the diameter of the secondary region and the equivalent curvature radius r, wherein the method comprises the following steps:

a. firstly, dividing the curved surface of the secondary region by adopting a Fresnel zone plate-like mode according to the phase change of 2pi or pi to obtain 3-5 annular zones;

b. if the phase dividing unit is 2pi, the binarization is carried out by changing pi, the setting larger than pi is a base surface, and the area smaller than pi is etched to remove the pi phase depth; if the phase dividing unit is pi, the binarization needs to be carried out by changing pi/2, the area which is larger than pi/2 is set as a base surface, and the area which is smaller than pi/2 is etched to remove the pi/2 phase depth;

c. and adjusting the etching width to ensure that the width of the etching groove is 30-100 microns, and finishing the division of the annular belt of the secondary area.

2. The ophthalmic lens with a contact microstructure according to claim 1, wherein: within the range of the distribution of the sub-zones, the first dioptric zone and the second dioptric zone form a mixed zone, wherein the area of the second dioptric zone formed by the sub-zones is 20-60% of the total area of the mixed zone.

3. The ophthalmic lens with a contact microstructure according to claim 2, wherein: the area of the second refraction zone, which is composed of the sub-zones, is 30-40% of the total area of the mixing zone.

4. The ophthalmic lens with a contact microstructure according to claim 2, wherein: the secondary regions are uniformly distributed in the mixing region.

5. The ophthalmic lens with a contact microstructure according to claim 1, wherein: the eye-side surface is spherical, and the object-side surface is spherical, aspherical or progressive.

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