JP4450480B2 - Progressive multifocal lens series - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to progressive multifocal lenses, and more particularly to progressive multifocal lenses for use as an aid to eye accommodation.
[0002]
[Prior art]
For correcting presbyopia, single focus lenses, bifocal lenses, progressive multifocal lenses, and the like are used. Among these lenses, progressive multifocal lenses, in particular, do not require eyeglasses to be exchanged or removed during distance vision and near vision, and there is no boundary in appearance as a bifocal lens. Therefore, in recent years, the demand for progressive multifocal lenses has increased considerably.
[0003]
The progressive multifocal lens is an auxiliary spectacle lens for adjusting power when the adjusting power of the eye declines and near vision becomes difficult. In general, in a progressive multifocal lens, the distance vision correction region (hereinafter referred to as “distance portion”) located above the lens during wearing and the near vision correction region (hereinafter referred to as “near vision”) located below. And a progressive region (hereinafter referred to as “intermediate portion”) in which the refractive power continuously changes between both regions. In the present invention, notations such as “upper”, “lower”, “horizontal” and “vertical” indicate the positional relationship in the lens when worn, and for example, the lower part of the distance part is the distance part. A region close to the middle portion is shown in FIG.
[0004]
FIG. 1 is a diagram showing an outline of region division of a progressive multifocal lens designed symmetrically. The progressive multifocal lens shown in FIG. 1 includes a distance portion F positioned above when worn, a near portion N positioned below, and an intermediate portion P whose refractive power continuously changes between the two regions. I have. Regarding the shape of the lens surface, the intersection line MM ′ between the section along the meridian running vertically from the upper part to the lower part of the lens surface and the lens surface on the object side (opposite to the eye) is the addition of the lens, etc. It is used as a reference line for expressing specifications, and is also used as an important reference line in lens design. In the progressive multifocal lens designed symmetrically in this way, the distance center OF of the distance portion F, the distance eye point E that is a fitting point, the geometric center OG of the lens surface, and the near center ON become the reference. It is on the center line MM ′.
[0005]
FIG. 2 shows a progressive multifocal lens (hereinafter referred to as an “asymmetric progressive multifocal lens”) in which the near portion N is arranged asymmetrically in consideration of the fact that the near vision center ON is closer to the nose side in the lens wearing state. FIG. Also in the asymmetric progressive multifocal lens as shown in FIG. 2, the cross section passing through the distance center OF of the distance portion F, the distance eye point E, the geometric center OG of the lens surface, and the near center ON, and the object side lens surface A center line MM ′ composed of a line intersecting with is used as a reference line.
[0006]
In the present invention, these reference lines are collectively referred to as “main meridian curve”. The center of the distance portion F and the center of the near portion N are positions to be used as a reference when measuring the lens power. The distance measurement reference point is called the distance center OF, and the near measurement reference point is used for near purposes. Called center ON. Further, the surface average refractive power at the distance center OF is a base curve, and the average spherical power of the transmitted light passing through the distance center OF is the reference average spherical power (hereinafter referred to as “distance power”) in the distance portion. And Usually, the near vision center ON coincides with the near vision eye point. However, the distance center and the near center here mean not a geometric center in each region but a functional center at the time of measuring and wearing the lens.
[0007]
In the present invention, the surface average refractive power (hereinafter referred to as “surface refractive power”) and the surface astigmatic difference (hereinafter referred to as “astigmatic difference”) are the maximum principal curvatures at arbitrary points on the progressive multifocal surface. Is represented by the following equations (a) and (b), where ψmax is the minimum principal curvature is ψmin, and the refractive index of the lens is n.
Surface refractive power = (ψmax + ψmin) × (n−1) / 2 (a)
Astigmatic difference = (ψmax−ψmin) × (n−1) (b)
[0008]
In the present invention, the average spherical power and astigmatism are expressed by the following equations when the maximum spherical power in a ray transmitted through an arbitrary point on the progressive multifocal surface is Dmax and the minimum spherical power is Dmin. Represented by (c) and (d), respectively.
Spherical power = (Dmax + Dmin) / 2 (c)
Astigmatism = (Dmax−Dmin) (d)
[0009]
In the present invention, the average spherical power is hereinafter referred to as “spherical power”. In addition, in the progressive multifocal lens, positive surface refractive power (or spherical power) is continuously added from the distance center OF toward the near center ON on the main meridian curve MM ′ passing through the substantially geometric center of the lens. Then, the value obtained by subtracting the surface refractive power (or spherical power) of the distance center OF from the surface refractive power (or spherical power) of the near vision center ON where the additional surface refractive power (or additional spherical power) is substantially maximized. This is called the addition of a progressive multifocal lens. In a progressive multifocal lens, a lens that is easy to wear is ideal in all areas of the distance portion F, the intermediate portion P, and the near portion N, which have a wide clear vision area, little distortion, distortion, and the like.
[0010]
[Problems to be solved by the invention]
By the way, in the conventional progressive multifocal lens, generally, the optical characteristics of the progressive multifocal surface (refractive surface) have been mainly discussed. That is, the performance of a progressive multifocal lens is often evaluated by, for example, the distribution of surface refractive power and the distribution of astigmatism on a progressive multifocal surface. Therefore, in the progressive multifocal surface, the designer obtains a distribution of surface refractive power that matches the application, to ensure a wide area called as clear vision area, an area having an astigmatic difference of a predetermined value or less, Furthermore, the main purpose has been to reduce the maximum astigmatic difference as much as possible, taking into consideration the flow, shaking, distortion, etc. of the image when the eyes are moved.
[0011]
However, in an actual spectacle lens, the optical characteristics of the progressive multifocal surface of the lens do not necessarily match the optical characteristics of the lens when the wearer uses the lens. Therefore, in recent years, in order to further improve the optical performance when the wearer actually uses the lens, not only the optical characteristics of the progressive multifocal plane, but also the evaluation of the optical performance in a state closer to the wearing state, In other words, the evaluation of the optical performance by the light beam transmitted through the lens has been performed.
[0012]
In general, the relationship between the lens curvature and the lens power that minimizes the astigmatism of the light transmitted through the lens can be obtained from, for example, a Chelning ellipse. That is, it is well known that the generation of astigmatism in the peripheral portion of the lens can be suppressed by selecting the optimal combination of curvatures obtained by this Chelning ellipse as the curvature of both surfaces of the lens. However, when the optimal combination of curvatures obtained by this Chelning ellipse is used, the curvature of the base curve tends to be large and the lens thickness tends to increase. For this reason, in progressive multifocal lenses in recent years, it is mainstream to select a curvature smaller than the curvature obtained by the combination of the above-mentioned optimal curvatures as the base curve due to the thinness of the lens and the appearance and manufacturing convenience. It has become.
[0013]
Therefore, there is a tendency between the surface refractive power distribution and astigmatic difference distribution on the progressive multifocal surface, and the spherical power distribution and astigmatism distribution of light rays that pass through the lens and enter the wearer's eye. In many cases, equality is limited to a region near the optical axis of the lens, such as a region where light rays from an object are incident at an angle close to the lens surface, that is, near a lens fitting point. On the other hand, since the light ray incident on the wearer's eye through a position away from the optical axis of the lens is incident obliquely with respect to the lens surface, the position where the astigmatism difference on the lens surface is almost zero. Astigmatism also occurs when the light beam passes through the lens, and enters the eye of the wearer in a state where the power is shifted from the distance power used as a reference. This tendency varies depending on the curvature and center thickness of the prescription surface of the lens, and becomes larger toward the periphery of the lens.
[0014]
In other words, in a progressive multifocal lens having a plurality of base curves, if the surface refractive power and astigmatic difference distribution of the progressive multifocal surface are designed to be equal for each base curve, the spherical power distribution and astigmatism of transmitted light The distribution of aberration is substantially different for each base curve. Therefore, in order to obtain a series of progressive multifocal lenses that have a plurality of base curves and whose optical characteristics of transmitted light such as spherical power distribution and astigmatism distribution in the wearing state are equal to the plurality of base curves. Therefore, a design that optimizes the progressive multifocal plane in consideration of the manufacturing range of each base curve is required.
[0015]
Recently, in a progressive multifocal lens, a conventional technique in which the optical performance of the transmitted light is evaluated has been proposed. However, in these conventional techniques, a region where astigmatism is a predetermined amount or less, specifically, a region where astigmatism is 0.50 diopter or less is defined as a clear vision region, and this clear vision region is secured widely. Most of them are only discussed. That is, in the prior art, there is little discussion about optimization regarding the distribution of spherical power.
[0016]
It is important and necessary to suppress astigmatism to a small amount as a standard for defining a clear visual field. However, it is not sufficient to define a clear vision area only with the magnitude of astigmatism for a distance portion that requires a particularly wide field of view in daily life. That is, in a region where the spherical power is greatly deviated from the distance dioptric power according to the prescription, even if the astigmatism is generally equal to or less than a predetermined amount defined as the clear vision region, the image is blurred due to the power misalignment. The person cannot see the object clearly in distance vision. The influence of the frequency shift in the distance portion for performing far vision is larger than the effect of the power shift in the near portion for performing near vision. For this reason, in the distance portion, it is very important to design in consideration of the frequency shift from the predetermined distance power than in the near portion.
[0017]
The present invention has been made in view of the above-described problems, and in a series of progressive multifocal lenses having a plurality of base curves designed so that the basic specifications of the lenses are substantially equal, all the base curves are provided. On the other hand, an object of the present invention is to provide a progressive multifocal lens that can make optical characteristics on wear almost equal and can set optical performance in a worn state well. An object of the present invention is to provide a progressive multifocal lens that can ensure a wide clear vision region with small astigmatism and less image blur due to power shift, particularly in a distance portion.
[0018]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the first invention of the present invention, at least one surface of the lens is adapted to a distant view along a main meridian curve dividing the refractive surface of the lens into a nose side region and an ear side region. Progressive to continuously connect the refractive power of the surfaces of both the distance vision correction area, the near vision correction area corresponding to the near view, and the distance vision correction area and the near vision correction area A series of progressive multifocal lenses having a plurality of base curves designed to have substantially the same basic lens specifications,
First base curve BC selected from the plurality of base curves _L In the first progressive multifocal lens having Pf, the surface average refractive power of an arbitrary point on the progressive multifocal surface in the distance vision correction region is Pf. _L And Pf _L -BC _L The area of the region satisfying ≦ 0.50 diopter is Sp _L age,
The first base curve BC _L And a second base curve BC selected from the plurality of base curves. _S The second progressive multifocal lens having substantially the same addition as that of the first progressive multifocal lens, and a surface average of arbitrary points on the progressive multifocal plane in the distance vision correction region Refractive power is Pf _S And Pf _S -BC _S The area of the region satisfying ≦ 0.50 diopter is Sp _S When
Sp _L > Sp _S (1)
A progressive multifocal lens characterized by satisfying the above conditions is provided.
[0019]
In the second invention of the present invention, at least on one surface of the lens, along the main meridian curve dividing the refractive surface of the lens into a nose region and an ear region, a distance vision correction region corresponding to a distant view, A near vision correction area corresponding to a near view, and a progressive area that continuously connects the refractive powers of the surfaces of both areas between the distance vision correction area and the near vision correction area, and a basic lens A series of progressive multifocal lenses with multiple base curves designed to be approximately equal in design specifications,
First base curve BC selected from the plurality of base curves _L In the first progressive multifocal lens having the above, the area of the area where the astigmatism difference in the distance vision correction area is 0.50 diopter or less is defined as Sa. _L age,
The first base curve BC _L And a second base curve BC selected from the plurality of base curves. _S And a second progressive multifocal lens having substantially the same addition as that of the first progressive multifocal lens, the astigmatic difference in the distance vision correction region is 0.50 diopter or less. Sa the area of the region _S When
Sa _L <Sa _S (2)
A progressive multifocal lens characterized by satisfying the above conditions is provided.
[0020]
In the third invention of the present invention, at least on one surface of the lens, along the main meridian curve dividing the refractive surface of the lens into a nose side region and an ear side region, a distance vision correction region corresponding to a distant view, A near vision correction area corresponding to a near view, and a progressive area that continuously connects the refractive powers of the surfaces of both areas between the distance vision correction area and the near vision correction area, and a basic lens A series of progressive multifocal lenses with multiple base curves designed to be approximately equal in design specifications,
First base curve BC selected from the plurality of base curves _L In the first progressive multifocal lens having Pf, the surface average refractive power of an arbitrary point on the progressive multifocal surface in the distance vision correction region is Pf. _L And Pf _L -BC _L The area of the region satisfying ≦ 0.50 diopter is Sp _L And the area of the area where the astigmatic difference in the distance vision correction area is 0.50 diopter or less is Sa. _L age,
The first base curve BC _L And a second base curve BC selected from the plurality of base curves. _S The second progressive multifocal lens having substantially the same addition as that of the first progressive multifocal lens, and a surface average of arbitrary points on the progressive multifocal plane in the distance vision correction region Refractive power is Pf _S And Pf _S -BC _S The area of the region satisfying ≦ 0.50 diopter is Sp _S And the area of the area where the astigmatic difference in the distance vision correction area is 0.50 diopter or less is Sa. _S When
Sp _L > Sp _S (1)
Sa _L <Sa _S (2)
A progressive multifocal lens characterized by satisfying the above conditions is provided.
[0021]
According to a preferred aspect of the first to third inventions, in the region located above the geometric center OG of the progressive multifocal lens,
The first base curve BC _L An arbitrary point on the isoplanar astigmatism curve where the astigmatic difference of the first progressive multifocal lens having λ is 0.50 diopter is M _L And the arbitrary point M from the main meridian curve _L The arbitrary point M from the geometric center OG when the horizontal distance to is x (mm) _L The vertical height up to h _L age,
Second base curve BC _S An arbitrary point on the isoplanar astigmatism curve in which the astigmatic difference of the second progressive multifocal lens having a value of 0.50 diopter is M _S And the arbitrary point M from the main meridian curve _S The arbitrary point M from the geometric center OG when the horizontal distance to is x (mm) _S The vertical height up to h _S When
In a region satisfying 15 ≦ | x |
h _L > H _S (3)
Always satisfy the conditions.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
As described above, in the prior art, a clear vision region is defined as a region where astigmatism is smaller than a predetermined amount, specifically, a region where astigmatism or astigmatism is within 0.50 diopters. However, it is not sufficient to define a clear visual field by such conditions especially in the distance portion. Therefore, in the present invention, it is considered important to suppress the deviation of the spherical power from the distance power to a small value in a wide range, and the distance power of astigmatism is smaller than the predetermined amount and the spherical power. A region where the amount of deviation from the lens is smaller than a predetermined amount, that is, a region satisfying both astigmatism and spherical power is defined as a clear vision region. The prior art has not proposed a progressive multifocal lens optimized to satisfy these two conditions simultaneously in a wide range of the distance portion.
[0023]
A general progressive multifocal lens has a plurality of base curves within a manufacturing range from a positive intensity number to a negative intensity number. Originally, it would be most preferable for the wearer to have an optimal progressive multifocal plane for each distance dioptric power, but in consideration of manufacturing convenience and cost advantages, it is usually a predetermined distance power. The same progressive multifocal plane is shared within the range of.
[0024]
In general, among the multiple base curves, the base curve requires a larger curvature in the production range where the distance power is more positive, whereas in the production range where the distance power is more negative. The curvature of the base curve is smaller. Therefore, in order to obtain the optical performance of transmitted light that meets the same design specifications within the manufacturing range manufactured using these same progressive multifocal surfaces, the refractive surface of the progressive multifocal lens having a plurality of base curves can be obtained. It is necessary to optimize the optical characteristics according to the manufacturing range and curvature of the base curve.
[0025]
In the present invention, the base curve corresponding to the production range including the distance diopter including 0.00 diopter is set as the reference base curve, and the progressive multifocal plane in the reference base curve is set as the reference design. Optical performance on wear such as astigmatism distribution is the target of optical performance in progressive multifocal lenses of all base curves.
[0026]
If the optical characteristics of the progressive multifocal surface (refractive surface), for example, the surface refractive power distribution and astigmatic difference distribution are designed to be equal to the reference design in the base curve of the production range where the distance power is more intense, The spherical power distribution and the astigmatism distribution are greatly different from the spherical power distribution and the astigmatism distribution in the reference design. In other words, when viewed from the optical characteristics of the refracting surface such as surface power and astigmatism, these multiple base curve lenses appear to be progressive multifocal lenses based on the same design, but the spherical power distribution of transmitted light Or different astigmatism distribution in terms of optical characteristics in the wearing state.
[0027]
Therefore, in the present invention, the surface refractive power distribution and the astigmatic difference distribution on the progressive multifocal surface are changed by a certain law depending on the base curve corresponding to the production range of each distance power. ing. With this configuration, in each progressive multifocal lens of the base curve, the optical characteristics in the wearing state such as the spherical power distribution and the astigmatism distribution of the transmitted light are made equal, and the astigmatism is small and the power in the distance portion. It is possible to ensure a wide clear vision area with little image blur due to deviation.
[0028]
In the present invention, it is considered that the minimum requirement for the spherical power of the clear vision region in far vision is that the eyeglass lens wearer can see an object at a distance of at least 2 m without feeling blurred image. ing. Therefore, the absolute value of the deviation amount of the spherical power from the distance power at an arbitrary point on the progressive multifocal surface of the distance portion is within 0.50 diopter, which relates to the spherical power of the clear vision region of the present invention. The condition (that is, the condition regarding the frequency deviation) is used. Regarding astigmatism, the amount of astigmatism that can be seen without feeling the flow of an image in far vision is generally limited to 0.50 diopter. Therefore, astigmatism is 0.50 diopter. The following is a condition regarding astigmatism in the clear vision region of the present invention.
[0029]
By the way, in a series of progressive multifocal lenses having a plurality of selectable base curves, when the surface refractive power distributions of two lenses having different base curves are approximately equal, the larger the curvature of the base curve, the longer the distance Since the area of the region where the spherical power in the portion is equal to or less than a predetermined value is narrowed, the clear vision region of the distance portion is narrowed. On the other hand, the smaller the curvature of the base curve, the larger the area where the spherical power in the distance portion is equal to or less than the predetermined amount, but the negative spherical power is added in the peripheral portion of the distance portion, and the area of negative overcorrection Can do. As a result, the clear vision area in the distance portion is narrowed, or the region satisfying the spherical power according to the prescription is expanded to the intermediate portion, so that the region of the spherical power that should be originally added to the intermediate portion and the near portion is narrowed. This causes problems such as a practical intermediate portion and a near portion becoming narrow.
[0030]
Therefore, in the first invention, the area Sp of the region where the difference between the surface refractive power Pf and the base curve BC in the distance portion on the progressive multifocal surface is 0.50 diopter or less satisfies the conditional expression (1). By improving the optical performance in the distance portion and ensuring a wide clear vision area, the optical performance on the wear for all the base curves between progressive multifocal lenses with different base curves is improved. These characteristics can be made almost equal.
[0031]
Further, in a series of progressive multifocal lenses having a plurality of selectable base curves, if the astigmatic difference distributions of two lenses having different base curves are approximately equal, even if the curvature of the base curve becomes larger Even if it is smaller, in any case, the area where the astigmatism in the distance portion is equal to or smaller than a predetermined value is narrowed, so that the clear vision area of the distance portion is narrowed. At this time, in the first progressive multifocal lens having a larger curvature of the base curve, the area Sa of the region where the astigmatic difference of the progressive multifocal surface in the distance portion is 0.50 diopter or less. _L The area Sa of the region where the astigmatism of the progressive multifocal surface of the reference design is 0.50 diopter or less ₀ If it is narrower than that, it is possible to secure a wide area in which the astigmatism in the transmitted light is 0.50 diopter or less.
[0032]
On the other hand, in the case of the second progressive multifocal lens in which the curvature of the base curve is smaller than that of the first progressive multifocal lens, the area Sa of the region where the astigmatic difference of the progressive multifocal surface is 0.50 diopter or less. _S By widening, it is possible to secure a wide area in which the astigmatism of the transmitted light in the distance portion is 0.50 diopter or less. Therefore, in the second invention, the distance Sa in the distance portion on the progressive multifocal surface in which the astigmatic difference is 0.50 diopter or less satisfies the conditional expression (2). While improving the optical performance in the area and securing a clear vision area, it is possible to make the optical characteristics on wear almost equal for all base curves between progressive multifocal lenses with different base curves. it can.
[0033]
Further, in the third invention, the difference between the surface refractive power Pf and the base curve BC in the distance portion on the progressive multifocal surface is 0.50 diopter or less by the combination of the first invention and the second invention. The area Sp of the area and the area Sa of the area where the astigmatism difference in the distance portion on the progressive multifocal surface is 0.50 diopter or less satisfy the conditional expressions (1) and (2), respectively. By improving the optical performance in the distance section and securing a wide clear vision area, the optical characteristics on wearing are almost the same for all base curves between progressive multifocal lenses with different base curves. Can be equal.
[0034]
Further, in the first to third inventions, the clear vision region in the distance side portion is widened by configuring so as to satisfy the conditional expression (3) in the region 15 mm or more away from the main meridian curve in the horizontal direction. The astigmatism distribution can be made substantially equal between the progressive multifocal lenses having different base curves while ensuring the same. When deviating from the range of the conditional expression (3), the astigmatism at the far side is deteriorated particularly in a progressive multifocal lens having a small curvature of the base curve. As a result, a progressive multifocal lens with a small curvature of the base curve is not preferable because a clear vision area becomes narrower than a progressive multifocal lens with a large base curve.
[0035]
In the region close to the distance eye point within 15 mm in the horizontal direction from the main meridian curve, the tendency of the surface astigmatism distribution and the tendency of the astigmatism distribution are close. For this reason, it is desirable that the conditional expression (3) of the present invention is satisfied in an area at least 15 mm away from the main meridian curve in the horizontal direction. However, in the present invention, it is needless to say that it is more preferable to satisfy the conditional expression (3) in a region separated by 10 mm or more in the horizontal direction.
[0036]
Embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 3 is a distribution diagram of surface addition average refractive power (hereinafter referred to as “surface addition refractive power”) of a progressive multifocal lens which is a reference design in the embodiment of the present invention. FIG. 4 is an astigmatic difference distribution diagram of the progressive multifocal lens according to the reference design of the present embodiment.
[0037]
In the progressive multifocal lens which is the reference design of the present embodiment, the outer diameter φ is 70 mm, the base curve BC is 3.10 diopter, the distance power Df is 0.00 diopter, and the addition Ad = 2. .00 diopter, the refractive index of the lens ne = 1.50, the distance eye point E is located 2 mm above the geometric center OG of the lens, and the distance center OF is 8 mm of the geometric center OG of the lens. Located above.
[0038]
Here, the surface addition power is a surface power obtained by subtracting the base curve from the surface average power at an arbitrary point on the progressive multifocal surface. In the present embodiment, for simplicity of explanation, the surface refractive power distribution is discussed with this surface additional refractive power distribution, but the essential meaning is equal between the surface additional refractive power and the surface average refractive power.
[0039]
On the other hand, FIG. 5 is a distribution diagram of the additional average spherical power (hereinafter referred to as “additional spherical power”) in the transmitted light of the progressive multifocal lens according to the reference design of the present embodiment. FIG. 6 is an astigmatism distribution diagram in the transmitted light of the progressive multifocal lens according to the reference design of this embodiment. Here, the additional spherical power is a spherical power obtained by subtracting the distance power of the light beam passing through the distance center OF from the spherical power of the light beam passing through an arbitrary point on the progressive multifocal surface. In the present embodiment, for simplicity of explanation, the spherical power distribution is discussed with this additional spherical power distribution, but the additional spherical power and the spherical power have the same essential meaning.
[0040]
In the progressive multifocal lens according to the present embodiment, the optical performance of the transmitted light in the reference design of the reference base curve BC = 3.10 diopter is set as the basic optical performance. For this reason, in the present embodiment, even in a progressive multifocal lens having another base curve, the additional spherical power distribution and astigmatism distribution in the progressive multifocal lens of the reference design as shown in FIGS. The design goal is to approximate the additional spherical power distribution and astigmatism distribution.
[0041]
FIG. 7 is a surface addition refractive power distribution diagram of a progressive multifocal lens as a first comparative example with respect to the reference design of the present embodiment. FIG. 8 is an astigmatic difference distribution diagram of the progressive multifocal lens according to the first comparative example. In the progressive multifocal lens according to the first comparative example, the surface addition refractive power distribution and the astigmatism distribution are almost the same as the surface addition refractive power distribution and astigmatism distribution of the progressive multifocal lens according to the reference design of the present embodiment. Designed to be equal.
[0042]
In the progressive multifocal lens according to the first comparative example, the outer diameter φ = 70 mm, the base curve BC = 5.60 diopter, the distance diopter Df = + 3.50 diopter, and the addition Ad = 2.00. The lens has a refractive index ne = 1.50, the distance eye point E is located 2 mm above the geometric center OG of the lens, and the distance center OF is 8 mm above the geometric center OG of the lens. positioned. Thus, the base curve and the distance power are different between the reference design of the present embodiment and the first comparative example. However, when comparing FIG. 3 and FIG. 4 with FIG. 7 and FIG. 8, it can be seen that even if the curvature of the base curve is different, the surface added refractive power distribution and the astigmatic difference distribution are almost equal.
[0043]
FIG. 9 is an additional spherical power distribution diagram of the transmitted light of the progressive multifocal lens according to the first comparative example. As described above, in the first comparative example, the surface added refractive power distribution is substantially equal to the reference design of the present embodiment. However, referring to FIG. 5 and FIG. It can be seen that the region of 50 diopters or less is narrower than the reference design of this embodiment, particularly in the distance side region. Therefore, in the first comparative example, in the vicinity of the distance eye point E, the wearer can only view far away only in this narrow region in the horizontal direction. In other words, in the first comparative example, the clear vision area in the distance portion is narrow.
[0044]
FIG. 10 is an astigmatism distribution diagram in the transmitted light of the progressive multifocal lens according to the first comparative example. As described above, in the first comparative example, the astigmatic difference distribution is substantially equal to the reference design of the present embodiment. However, when comparing FIG. 6 and FIG. 10, astigmatism is 0.50 in the distance portion. It can be seen that the area below the diopter is narrower than the reference design of the present embodiment, and the astigmatism is significantly deteriorated especially in the upper part of the distance portion. For this reason, in the first comparative example, the clear vision area in the distance portion is narrow.
[0045]
As described above, referring to FIG. 9 and FIG. 10, in the progressive multifocal lens of the first comparative example having a base curve having a curvature larger than that of the reference design of the present embodiment, the surface added refractive power distribution of the progressive multifocal surface. When the astigmatic difference distribution is substantially equal to the reference design of this embodiment, the region where the added spherical power in transmitted light is 0.50 diopter or less and the astigmatism is 0.50 diopter or less is the reference design of this embodiment. It turns out that it becomes very narrow. Therefore, in the progressive multifocal lens of the first comparative example, the clear vision area in the distance portion is very narrow, and the lens is inferior in optical performance different from the reference design of the present embodiment.
[0046]
FIG. 11 is a surface addition refractive power distribution diagram of the first progressive multifocal lens which is the progressive multifocal lens according to the present embodiment and has a base curve having a curvature larger than that of the reference design. In the first progressive multifocal lens according to the present embodiment, as in the first comparative example, the outer diameter φ is 70 mm, the base curve BC is 5.60 diopters, and the distance power Df is +3.50 diopters. Yes, the addition is Ad = 2.00 diopter, the refractive index of the lens is ne = 1.50, the distance eye point E is located 2 mm above the geometric center OG of the lens, and the distance center OF is It is located 8 mm above the geometric center OG of the lens.
[0047]
As can be seen from a comparison between FIG. 3 and FIG. 11, in the first progressive multifocal lens of the present embodiment, the area of the area where the surface addition refractive power in the distance portion is 0.50 diopter or less is larger than that in the case of the reference design. It is getting wider. Furthermore, in the first progressive multifocal lens of the present embodiment, negative surface refractive power is added to the base curve at the periphery of the lens above the distance center OF of the distance portion.
[0048]
FIG. 12 is an astigmatic difference distribution diagram of the first progressive multifocal lens according to the present embodiment. As can be seen from the comparison between FIG. 4 and FIG. 12, in the first progressive multifocal lens of this embodiment, the area of the astigmatic difference of 0.50 diopter or less in the distance portion is narrower than in the reference design. Especially in the far side area.
[0049]
FIG. 13 is an additional spherical power distribution diagram of transmitted light of the first progressive multifocal lens according to the present embodiment. As can be seen from a comparison between FIG. 9 and FIG. 13, in the first progressive multifocal lens of the present embodiment, the area where the additional spherical power is 0.50 diopter or less in the distance portion is the surface refraction of the progressive multifocal surface. The force distribution is much wider than that of the first comparative example in which the force distribution is almost equal to the reference design of the present embodiment, and is particularly wide at the distance side portion. As a result, as can be seen from a comparison between FIG. 5 and FIG. 13, the first progressive multifocal lens of this embodiment has an additional spherical power closer to the additional spherical power distribution of the progressive multifocal lens according to the reference design of this embodiment. It is a distributed lens.
[0050]
FIG. 14 is an astigmatism distribution diagram in the transmitted light of the first progressive multifocal lens according to the present embodiment. As can be seen from the comparison between FIG. 10 and FIG. 14, in the first progressive multifocal lens of this embodiment, the region with astigmatism of 0.50 diopter or less in the distance portion is the astigmatism of the progressive multifocal surface. Compared with the case of the first comparative example in which the difference distribution is substantially equal to the reference design of the present embodiment, it is much wider especially in the upper part of the lens. As a result, as can be seen from the comparison between FIG. 6 and FIG. 14, the first progressive multifocal lens of this embodiment is astigmatism closer to the astigmatism distribution of the progressive multifocal lens according to the reference design of this embodiment. It is a distributed lens.
[0051]
As described above, referring to FIG. 13 and FIG. 14, the first embodiment of the present embodiment has a base curve with a larger curvature than the reference design of the present embodiment, and corresponds to a manufacturing range with a more positive power for distance use. In the 1 progressive multifocal lens, a wide clear vision area having an additional spherical power of 0.50 diopter or less and an astigmatism of 0.50 diopter or less is ensured in the distance portion, and wearing in the reference design of the present embodiment. It can be close to optical performance.
[0052]
FIG. 15 is a surface addition refractive power distribution diagram of a progressive multifocal lens as a second comparative example with respect to the reference design of the present embodiment. FIG. 16 is an astigmatic difference distribution diagram of the progressive multifocal lens according to the second comparative example. In the progressive multifocal lens according to the second comparative example, the surface addition refractive power distribution and astigmatic difference distribution are substantially the same as the surface addition refractive power distribution and astigmatic difference distribution of the progressive multifocal lens according to the reference design of this embodiment. Designed to be equal.
[0053]
In the progressive multifocal lens according to the second comparative example, the outer diameter φ = 70 mm, the base curve BC = 2.00 diopter, the distance diopter Df = −2.50 diopter, and the addition Ad = 2. 00 diopter, the refractive index of the lens ne = 1.50, the distance eye point E is located 2 mm above the geometric center OG of the lens, and the distance center OF is 8 mm above the geometric center OG of the lens Is located. As described above, the base curve and the distance power are different between the reference design of the present embodiment and the second comparative example. However, comparing FIG. 3 and FIG. 4 with FIG. 15 and FIG. 16, it can be seen that even if the curvature of the base curve is different, the surface added refractive power distribution and the astigmatic difference distribution are almost equal.
[0054]
FIG. 17 is an additional spherical power distribution diagram of transmitted light of the progressive multifocal lens according to the second comparative example. As described above, in the second comparative example, the surface added refractive power distribution is substantially equal to the reference design of the present embodiment, and the area where the additional spherical power is 0.50 diopter or less in the distance portion is the present embodiment. It is wider than the standard design. However, referring to FIG. 5 and FIG. 17 in comparison, in the second comparative example, the area of the spherical power that should be originally added to the side part of the intermediate part or the near part is narrower than the reference design of the present embodiment. You can see that
[0055]
FIG. 18 is an astigmatism distribution diagram in the transmitted light of the progressive multifocal lens according to the second comparative example. As described above, in the second comparative example, the astigmatic difference distribution is substantially equal to the reference design of the present embodiment. However, when comparing FIG. 6 and FIG. 18, astigmatism is 0.50 in the distance portion. It can be seen that the area below the diopter is narrow only in the vicinity of the distance center OF. In the second comparative example, astigmatism is increased in the peripheral portion of the distance portion, so that it becomes a cause of increase in image flow, blurring, shaking, distortion and the like.
[0056]
As described above, with reference to FIGS. 17 and 18, in the progressive multifocal lens of the second comparative example having the base curve having a smaller curvature than the reference design of the present embodiment, the surface added refractive power distribution of the progressive multifocal surface. When the astigmatic difference distribution is substantially equal to the reference design of this embodiment, the region where the added spherical power in transmitted light is 0.50 diopter or less and the astigmatism is 0.50 diopter or less is the reference design of this embodiment. It turns out that it becomes very narrow. Therefore, in the progressive multifocal lens of the second comparative example, the clear vision area in the distance portion is very narrow, and the lens has inferior optical performance different from the reference design of the present embodiment.
[0057]
FIG. 19 is a surface addition refractive power distribution diagram of the second progressive multifocal lens which is the progressive multifocal lens according to the present embodiment and has a base curve having a smaller curvature than that of the reference design. In the second progressive multifocal lens according to this embodiment, as in the second comparative example, the outer diameter φ = 70 mm, the base curve BC = 2.00 diopter, and the distance power Df = −2.50 diopter. The addition is Ad = 2.00 diopter, the refractive index of the lens is ne = 1.50, the distance eye point E is located 2 mm above the geometric center OG of the lens, and the distance center OF Is located 8 mm above the geometric center OG of the lens.
[0058]
As can be seen from a comparison between FIG. 3 and FIG. 19, in the second progressive multifocal lens of this embodiment, a positive surface addition refractive power of 0.50 diopter or more with respect to the surface addition refractive power at the distance center OF is obtained. It is added to the distance side. Furthermore, in the second progressive multifocal lens of the present embodiment, the area of the area where the surface addition refractive power is 0.50 diopter or less in the distance portion is narrower than in the case of the reference design of the present embodiment.
[0059]
FIG. 20 is an astigmatic difference distribution diagram of the second progressive multifocal lens according to the present embodiment. As can be seen from the comparison between FIG. 4 and FIG. 20, in the second progressive multifocal lens of this embodiment, the area of the astigmatic difference of 0.50 diopter or less in the distance portion is wider than that in the reference design. In particular, it is wider under the side part for distance near the middle part.
[0060]
FIG. 21 is an additional spherical power distribution diagram of transmitted light of the second progressive multifocal lens according to the present embodiment. As can be seen from the comparison between FIG. 17 and FIG. 21, in the second progressive multifocal lens of this embodiment, the area where the additional spherical power is 0.50 diopter or less in the distance portion is the surface refraction of the progressive multifocal surface. The force distribution is much wider than in the case of the second comparative example in which the force distribution is substantially equal to the reference design of the present embodiment, and the spherical power distribution from the middle portion to the near portion side is also improved. As a result, as can be seen from a comparison between FIG. 5 and FIG. 21, the second progressive multifocal lens of the present embodiment has an additional spherical power closer to the additional spherical power distribution of the progressive multifocal lens according to the reference design of the present embodiment. It is a distributed lens.
[0061]
FIG. 22 is an astigmatism distribution diagram in the transmitted light of the second progressive multifocal lens according to the present embodiment. As can be seen from the comparison between FIG. 18 and FIG. 22, in the second progressive multifocal lens of the present embodiment, the astigmatism region of 0.50 diopter or less in the distance portion is the astigmatism of the progressive multifocal surface. Compared to the case of the second comparative example in which the difference distribution is substantially equal to the reference design of the present embodiment, it is much wider especially in the upper part of the lens. As a result, as can be seen from a comparison between FIG. 6 and FIG. 22, the second progressive multifocal lens of this embodiment is astigmatism closer to the astigmatism distribution of the progressive multifocal lens according to the reference design of this embodiment. It is a distributed lens.
[0062]
As described above, referring to FIG. 21 and FIG. 22, the first embodiment of the present embodiment has a base curve with a smaller curvature than that of the reference design of the present embodiment and corresponds to a manufacturing range in which the distance power is more negative. In the 2 progressive multifocal lens, in the distance portion, a large clear vision area having an additional spherical power of 0.50 diopter or less and an astigmatism of 0.50 diopter or less is secured, and the wearing in the reference design of the present embodiment. It can be close to optical performance.
[0063]
It is obvious that the present invention can be applied to progressive multifocal lenses of various specifications and materials without being limited to the above-described embodiments.
[0064]
【The invention's effect】
As described above, according to the present invention, in a series of progressive multifocal lenses having a plurality of base curves designed so that the basic specifications of the lenses are substantially equal, all the base curves can be worn. Thus, it is possible to realize a progressive multifocal lens that can substantially equalize the optical characteristics of the lens and can set the optical performance in a worn state. In particular, in the distance portion, it is possible to secure a wide clear vision area with small astigmatism and less image blur due to power deviation.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a region division of a progressive multifocal lens designed symmetrically.
FIG. 2 is a schematic diagram of a region classification of an asymmetric progressive multifocal lens in which a near portion N is arranged asymmetrically in consideration of the fact that the near center ON is closer to the nose side when the lens is worn.
FIG. 3 is a distribution diagram of surface addition refracting power of a progressive multifocal lens serving as a reference design in the embodiment of the present invention.
FIG. 4 is an astigmatic difference distribution diagram of the progressive multifocal lens according to the reference design of the present embodiment.
FIG. 5 is a distribution diagram of additional spherical power in transmitted light of the progressive multifocal lens according to the reference design of the present embodiment.
FIG. 6 is an astigmatism distribution diagram in the transmitted light of the progressive multifocal lens according to the reference design of the present embodiment.
FIG. 7 is a surface addition refractive power distribution diagram of a progressive multifocal lens as a first comparative example with respect to the reference design of the present embodiment.
FIG. 8 is an astigmatic difference distribution diagram of the progressive multifocal lens according to the first comparative example.
FIG. 9 is an additional spherical power distribution diagram of the transmitted light of the progressive multifocal lens according to the first comparative example.
FIG. 10 is an astigmatism distribution diagram in the transmitted light of the progressive multifocal lens according to the first comparative example.
FIG. 11 is a surface addition refracting power distribution diagram of a first progressive multifocal lens that is a progressive multifocal lens according to the present embodiment and has a base curve having a curvature larger than that of a reference design.
FIG. 12 is an astigmatic difference distribution diagram of the first progressive multifocal lens according to the present embodiment.
FIG. 13 is an additional spherical power distribution diagram of transmitted light of the first progressive multifocal lens according to the present embodiment.
FIG. 14 is an astigmatism distribution diagram of transmitted light of the first progressive multifocal lens according to the present embodiment.
FIG. 15 is a surface addition refractive power distribution diagram of a progressive multifocal lens as a second comparative example with respect to the reference design of the present embodiment;
FIG. 16 is an astigmatic difference distribution diagram of a progressive multifocal lens according to a second comparative example.
FIG. 17 is an additional spherical power distribution diagram of transmitted light of a progressive multifocal lens according to a second comparative example.
FIG. 18 is an astigmatism distribution diagram of transmitted light of a progressive multifocal lens according to a second comparative example.
FIG. 19 is a diagram showing a surface addition refractive power distribution of a second progressive multifocal lens that is a progressive multifocal lens according to the present embodiment and has a base curve having a curvature smaller than that of a reference design.
FIG. 20 is an astigmatic difference distribution diagram of the second progressive multifocal lens according to the present embodiment.
FIG. 21 is an additional spherical power distribution diagram of transmitted light of the second progressive multifocal lens according to the present embodiment.
FIG. 22 is an astigmatism distribution diagram in the transmitted light of the second progressive multifocal lens according to the present embodiment.
[Explanation of symbols]
F Distance Department
N near part
P Middle part
MM 'principal meridian curve
OF distance center
E Eye for distance
OG geometric center
ON Near center

Claims (4)

A distance vision correction area corresponding to a distant view and a near vision correction corresponding to a foreground along a main meridian curve that divides the refractive surface of the lens into a nose area and an ear area on at least one surface of the lens. A progressive region that continuously connects the refractive powers of the surfaces of both regions between the distance vision correction region and the near vision correction region, and has a plurality of base curves, A series of progressive multifocal lenses in which the spherical power distribution or the astigmatism distribution in the wearing state which is an optical characteristic is equal to a plurality of base curves ,
In the first progressive power multifocal lens having a first base curve BC _L selected from said plurality of base curves, the average surface refracting power of an arbitrary point on the progressive power multifocal surface in the far vision correction area and Pf _L , Pf _L −BC _L ≦ 0.50 The area of the region satisfying diopter is Sp _L ,
The second base curve BC _S is substantially smaller than the first base curve BC _L and selected from the plurality of base curves, and is substantially the same as the addition power of the first progressive multifocal lens. In the second progressive multifocal lens having an addition power, the surface average refractive power at an arbitrary point on the progressive multifocal surface in the distance vision correction region is Pf _S, and Pf _S −BC _S ≦ 0.50 diopter is satisfied. When the area of the region to be processed is Sp _S ,
Sp _L > Sp _S (1)
Progressive multifocal lens series characterized by satisfying the above conditions. A distance vision correction area corresponding to a distant view and a near vision correction corresponding to a foreground along a main meridian curve that divides the refractive surface of the lens into a nose area and an ear area on at least one surface of the lens. A progressive region that continuously connects the refractive powers of the surfaces of both regions between the distance vision correction region and the near vision correction region, and has a plurality of base curves, A series of progressive multifocal lenses in which the spherical power distribution or the astigmatism distribution in the wearing state which is an optical characteristic is equal to a plurality of base curves ,
In the first progressive power multifocal lens having a first base curve BC _L selected from said plurality of base curves, the area of the region surface astigmatism in the far vision correction area is not more than 0.50 diopters Sa _L age,
The second base curve BC _S is substantially smaller than the first base curve BC _L and selected from the plurality of base curves, and is substantially the same as the addition power of the first progressive multifocal lens. In the second progressive multifocal lens having the addition power, when the area of the area where the astigmatic difference in the distance vision correction area is 0.50 diopter or less is Sa _S ,
Sa _L <Sa _S (2)
Progressive multifocal lens series characterized by satisfying the above conditions. A distance vision correction area corresponding to a distant view and a near vision correction corresponding to a foreground along a main meridian curve that divides the refractive surface of the lens into a nose area and an ear area on at least one surface of the lens. A progressive region that continuously connects the refractive powers of the surfaces of both regions between the distance vision correction region and the near vision correction region, and has a plurality of base curves, A series of progressive multifocal lenses in which the spherical power distribution or the astigmatism distribution in the wearing state which is an optical characteristic is equal to a plurality of base curves ,
In the first progressive power multifocal lens having a first base curve BC _L selected from said plurality of base curves, the average surface refracting power of an arbitrary point on the progressive power multifocal surface in the far vision correction area and Pf _L , Pf _L −BC _L ≦ 0.50 The area of the area satisfying diopter is designated as Sp _L, and the area of the area where the astigmatic difference in the distance vision correction area is 0.50 diopter or less is designated as Sa _L ,
The second base curve BC _S is substantially smaller than the first base curve BC _L and selected from the plurality of base curves, and is substantially the same as the addition power of the first progressive multifocal lens. In the second progressive multifocal lens having an addition power, the surface average refractive power at an arbitrary point on the progressive multifocal surface in the distance vision correction region is Pf _S, and Pf _S −BC _S ≦ 0.50 diopter is satisfied. When the area of the area to be treated is Sp _S and the area of the area where the astigmatic difference in the distance vision correction area is 0.50 diopter or less is Sa _S ,
Sp _L > Sp _S (1)
Sa _L <Sa _S (2)
Progressive multifocal lens series characterized by satisfying the above conditions. In a region located above the geometric center OG of the progressive multifocal lens,
Any point of the first progressive surface astigmatism multifocal lens on Hitoshimen astigmatism curve is 0.50 diopters with said first base curve BC _L and M _L, the optionally from said principal meridional curve the geometric center from OG vertical to the arbitrary point M _L height when the horizontal distance is x (mm) and h _L to the point M _L of
An arbitrary point on the isosurface astigmatism curve in which the surface astigmatism of the second progressive multifocal lens having the second base curve BC _S is 0.50 diopter is defined as M _S, and the arbitrary meridian curve from the main meridian curve when the horizontal distance to the M _S point of the geometrical center vertical height from OG to said arbitrary point M _S when the x (mm) was h _S,
In a region satisfying 15 ≦ | x |
h _L > h _S (3)
The progressive multifocal lens series according to any one of claims 1 to 3, wherein the following condition is always satisfied.

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