WO2014091529A1 - Contact lens - Google Patents

Abstract

This contact lens, for which QOV is improved by providing an optical center that is shifted from the geometrical center of the lens, has a novel structure such that the contact lens can be manufactured and handled without distinguishing between a lens for the left eye and for the right eye and also such that a mark or the like showing the shift direction for the optical center is unnecessary. A contact lens (10) is provided with first strength areas (20) and a second strength area (22) in an optical area (14). A pair of first strength areas (20) is provided linearly symmetrical with respect to a radial line of symmetry (24) which is a line in the radial direction of the lens, and also a second strength area (22) is provided on the outer peripheral sides of that pair of first strength areas (20). The optical area (14) has a linear symmetrical shape with respect to the radial line of symmetry (24). Furthermore, a circumferential direction positioning means (36) that imparts a stable position in the circumferential direction of the lens such that the radial line of symmetry (24) extends in the vertical direction of the wearing eye in a worn state and either of the pair of first strength areas (20) is aligned with the center of the pupil (32) of the wearing eye.

Description

contact lens

The present invention relates to a contact lens, and more particularly, to a contact lens provided with a first power region and a second power region in which different lens powers are set in the optical region.

Conventionally, as a kind of contact lens, one having a plurality of power regions in which different lens powers are set in the optical region is known. For example, in a contact lens for correcting presbyopia, the lens power required for near vision differs from the lens power required for far vision. And a distance lens in which the distance power is set is prescribed for presbyopia correction. Specifically, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 61-272717), a contact having a structure in which a near area and a far area are formed concentrically with respect to a lens geometric center. The lens is known.

By the way, in the wearing state in which the contact lens is superimposed on the cornea of the human eye, the pupil center located on the central axis of the eye optical system often deviates from the geometric center of the contact lens. The reason is that the curvature distribution on the corneal surface of the human eye is not uniform, so that the contact lens is easily shifted to the ear side, and the pupil center is eccentric to the nose side relative to the geometric center of the cornea. This is considered to be due to such reasons.

As described above, when the pupil center deviates from the geometric center of the contact lens under the wearing state, the conventional structure in which the near area and the far area are provided concentrically with the lens geometric center as described in Patent Document 1 above. The contact lens has a problem that it is difficult to obtain a sufficient quality of view (QOV). Therefore, the present applicant has proposed a contact lens in which the optical center axis of the optical region is biased from the lens geometric center to the nose side in Japanese Patent Laid-Open No. 6-289329 (Patent Document 2). In the contact lens described in Patent Document 2, it is possible to suppress the distance between the pupil center and the optical center axis in the worn state, and the QOV can be improved.

However, in a contact lens in which the optical center of the optical region is deviated from the lens geometric center, the optical region is asymmetrical, so it is necessary to standardize, manufacture, manage, and provide the left eye and right eye separately. Since the user also has to use the right and left separately, there is a problem that not only the manufacture and management of the contact lens manufacturer / manufacturer becomes complicated, but also the handling at the time of use by the user becomes troublesome. In particular, if the left eye and the right eye are worn oppositely, the optical area is biased to the opposite side with respect to the pupil center of the worn eye, so that the QOV is greatly reduced, and the user is anxious. And there was a risk of distrust.

Further, in the contact lens described in Patent Document 2, it is necessary to wear the optical center with respect to the lens geometric center in a specific direction on the cornea. Therefore, a mark or the like must be attached so that the eccentric direction of the optical center with respect to the lens geometric center can be visually confirmed, and a special manufacturing process such as printing or engraving is required, and the user confirms a small mark. In addition, there is a problem that it is necessary to wear it while paying attention to the lens direction.

Japanese Patent Laid-Open No. 61-272717 JP-A-6-289329

Here, the present invention has been made in the background as described above, and the solution is to improve the QOV by providing the optical center deviating from the lens geometric center. Provided is a contact lens having a novel structure that can be manufactured and handled without distinction for the left eye and right eye, and that does not require a mark or the like indicating the deviation direction of the optical center. There is.

Hereinafter, embodiments of the present invention made to solve the above-described problems will be described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible.

That is, the feature of the first aspect of the present invention is that the optical region located in the center portion of the lens is provided with a first power region and a second power region in which different lens powers are set. A pair of the first power regions are provided symmetrically with respect to a symmetrical radial line that is one lens radial direction line, and the second power region is disposed on the outer peripheral side of the pair of first power regions. A power region is provided, and the optical region as a whole has a line-symmetric shape with respect to the symmetrical radial line, and the symmetrical radial line extends in the vertical direction of the wearing eye in the wearing state, and The contact lens is provided with circumferential positioning means for providing a stable position in the lens circumferential direction so that either one of the power regions is aligned with the pupil center of the wearing eye.

In the contact lens having a structure according to the present invention, the first and second power regions are provided symmetrically on both the left and right sides with respect to the radial line extending in the substantially vertical direction under wearing conditions. Therefore, even when the contact lens is worn in either the left eye or the right eye and the geometric center of the contact lens is deviated to either the left or right side with respect to the pupil center, a substantially similar appearance quality can be exhibited. As a result, it is not necessary to standardize and manufacture and manage the left eye and right eye separately, thereby reducing the burden on the contact lens manufacturer and user. In particular, in the contact lens according to the present invention, the left and right separate standards are not required, so even when lenses are provided by prospective production, for example, the inventory amount can be halved compared to the conventional, for manufacturing and management. It is possible to greatly reduce the necessary cost.

According to a second aspect of the present invention, in the contact lens according to the first aspect, the first power region has a vision correction power for near vision, while the second power region is for distance vision. It has a vision correction power.

According to a third aspect of the present invention, in the contact lens according to the first aspect, the first power region has a vision correction power for distance vision while the second power region is near vision. It has a vision correction power for use.

In the contact lens according to the second and third aspects, for example, reading under a work lamp or input operation with a computer monitor under a wearing state in which the lens geometric center is biased to the ear side with respect to the pupil center. Even when the pupil diameter is reduced and reduced in near vision, the one of the pair of first power areas or the second power area provided symmetrically with respect to the lens geometric center is in the pupil. It can be positioned stably. On the other hand, for example, when viewing from a distance during night vehicle driving, the pupil diameter increases and the diameter increases, so that the first power region and the second power region can be positioned with sufficient area in the pupil. Thus, the correction effect by the first power region and the second power region can be effectively exhibited as a simultaneous vision type contact lens.

According to a fourth aspect of the present invention, in the contact lens according to the first aspect, the first power region has a vision correction power for photopic vision while the second power region is for dark vision. It has a visual acuity correction frequency of.

In the contact lens of this aspect, even if the pupil diameter is reduced and reduced in the photopic vision in a wearing state where the lens geometric center is biased to the ear side with respect to the pupil center, One of the pair of first power regions provided symmetrically can be stably positioned in the pupil. On the other hand, in the case of scotopic vision, since the pupil diameter increases and the diameter increases, the second power region in addition to the first power region can be positioned with a sufficient area in the pupil. As a contact lens, the correction effect by the second power region can be effectively exhibited. Note that the photopic state is, for example, outdoors in the daytime, and generally has a pupil diameter of about 2 to 3 mm, although it depends on the race and individual differences.

According to a fifth aspect of the present invention, in the contact lens according to the second aspect, the first power region has an added power of +0.25 to +4.0 diopters relative to the second power region. It is set.

According to a sixth aspect of the present invention, in the contact lens according to the third aspect, +0.25 to +4.0 diopters are added to the second power region relative to the first power region. The frequency is set.

In the contact lens of the fifth aspect, a simultaneous vision type contact lens, for example, for presbyopia correction, in which the first power region is for near vision and the second power region is for distance vision is effective. Can be realized. Specifically, for example, when the second frequency region is −3.0D, the first frequency region is set within a range of −2.75D to + 1.0D.

Alternatively, in the contact lens of the sixth aspect, there is a simultaneous vision type contact lens, for example, for presbyopia correction, in which the first power region is for far vision and the second power region is for near vision. It can be realized effectively. Specifically, for example, when the first frequency region is −3.0D, the second frequency region is set within a range of −2.75D to + 1.0D.

According to a seventh aspect of the present invention, in the contact lens according to any one of the first to sixth aspects, the entire lens is axisymmetric with respect to the symmetrical radial line.

In the contact lens of this aspect, the overall shape including not only the optical region but also the peripheral part is axisymmetric with respect to the symmetrical radial line extending in the vertical direction in the worn state. However, even if it is worn on either the left or right eye, the same characteristics are exhibited.

According to an eighth aspect of the present invention, in the contact lens according to any one of the first to seventh aspects, the optical region is axisymmetric with respect to an orthogonal radial line orthogonal to the symmetrical radial line. is there.

In the contact lens of this aspect, optical characteristics that are line symmetric not only in the left-right direction but also in the up-down direction in the worn state are exhibited, so that handling at the time of wearing by the user becomes even easier. Further, since it is not necessary to specify the vertical direction at the time of wearing, it is possible to adopt a configuration capable of positioning without distinguishing the vertical direction as the circumferential positioning means, and the degree of freedom in design is increased.

According to a ninth aspect of the present invention, there is provided the contact lens according to the eighth aspect, wherein the circumferential positioning means is arranged in an up-and-down direction regardless of which of the ends in the symmetric radial direction is positioned upward in a worn state. A stable position in the lens circumferential direction is given in each of two directions on the circumference as the reversal position.

In the contact lens of this aspect, stable positions are given in two directions on the circumference. Therefore, even if the user wears the eyes without being particularly conscious of the direction, the user is more quickly guided to the target stable position. The intended effects such as eyesight correction will be exhibited.

According to a tenth aspect of the present invention, in the contact lens according to any one of the first to eighth aspects, the circumferential positioning means is configured such that a specific end in the symmetric radial direction is positioned upward in a worn state. In addition, a stable position in the circumferential direction of the lens is provided in one direction on the circumference.

In the contact lens of this aspect, since a stable position is given in one direction on the circumference, for example, in the optical region and / or the peripheral portion, even when a vertically asymmetric shape is adopted with respect to an orthogonal diameter line orthogonal to the symmetry diameter line, The user can wear without being aware of up and down, and can stably obtain a desired visual acuity correction effect, a feeling of wearing, and the like.

An eleventh aspect of the present invention is the contact lens according to any one of the first to seventh aspects, wherein one side of both side regions partitioned by an orthogonal diameter line orthogonal to the symmetry diameter line The pair of first power regions are provided in a biased manner so that the optical region is asymmetric with respect to the orthogonal radial line, and the circumferential positioning means is in the symmetrical radial direction in a worn state. It is a contact lens that gives a stable position in the circumferential direction of the lens in one direction on the circumference so that a specific end is positioned upward.

In the contact lens of this aspect, in consideration of the deviation direction and the amount of deviation of the pupil center with respect to the geometric center of the contact lens in the worn state, the first in the contact lens is not only in the left and right direction but also in the vertical direction in the worn state. It becomes possible to set the center position of the frequency region more appropriately. Specifically, for near vision work such as desk work and reading, for example, the near center of the pupil is likely to be biased downward in the nose side with respect to the geometric center of the contact lens in the worn state. It is possible to set the first power region in which the optical characteristics are set by deviating downward in a worn state with respect to the orthogonal diameter line, thereby enabling a more appropriate visual acuity correction effect or the like in near vision work It becomes possible to provide.

According to a twelfth aspect of the present invention, in the contact lens according to any one of the first to eleventh aspects, the pair of first power regions are provided apart from each other.

In the contact lens of this aspect, since the pair of first power regions are provided in the worn contact lens so as to be separated from each other in the left-right direction, the pupil center is located on any first power region Even in this case, it is possible to set the second frequency region or the transition region from the first frequency region to the second frequency region over the entire circumference of the first frequency region. Therefore, not only the first power region but also the second power region, or the optical characteristics by the transition region in which the lens power between the first power region and the second power region is set are more effective. To be able to get to.

A thirteenth aspect of the present invention is the contact lens according to the twelfth aspect, wherein the pair of first power regions provided apart from each other is placed on the pupil center in a worn state. Depending on the amount of deviation of the center of the pupil with respect to the lens stable position in the wearing state so that the influence of the other first power region is substantially avoided with respect to the first power region that is positioned Thus, a separation distance between the pair of first power regions is set.

In the contact lens of this aspect, when the pupil center is located on one first power region in the wearing state, the adverse effect on the appearance due to the other first power region is more effectively prevented, and further Excellent visual quality is achieved. In the orthogonal radial direction of the contact lens, the distance L between the pair of first power regions is preferably 0.10 mm or more, and more preferably 0.30 mm or more.

According to a fourteenth aspect of the present invention, in the contact lens according to any one of the first to thirteenth aspects, the geometric center point in the pair of first power regions is 0. 0 with respect to the symmetrical radial line. They are biased to the opposite sides with respect to the symmetrical diameter line with a deflection amount of 30 mm to 4.0 mm.

In the contact lens of this aspect, in the average human eye, the amount of deviation of the contact lens from the corneal center due to the corneal shape, etc. and the amount of deviation of the visual axis with respect to the optics in the human eye (deviation amount of the pupil center relative to the corneal center) are considered. Thus, it is possible to provide a contact lens capable of giving a good QOV by the first power region. If the deviation is outside the range of 0.30 mm to 4.0 mm, the optical action due to the first power region under the condition that the pupil diameter is small is not sufficiently exhibited, or the pupil diameter is large. Under such circumstances, the quality of the appearance may be deteriorated due to an adverse effect of the other first frequency region.

According to a fifteenth aspect of the present invention, in the contact lens according to any one of the first to fourteenth aspects, the first power region has an outer diameter of 1.0 to 2.5 mm. It is.

In the contact lens of this aspect, the optical action by the first power region can be stably and more effectively enjoyed.

A sixteenth aspect of the present invention is the contact lens according to any one of the first to fifteenth aspects, wherein the pair of first power regions are circular regions.

In the contact lens according to this aspect, the first power region has a circular outer peripheral shape, which corresponds to a substantially circular pupil outer peripheral shape. As a result, the optical characteristics of the first power region in the substantially central portion of the pupil and the optical properties of the second power region in the substantially outer peripheral portion of the pupil can efficiently secure the effective area of each power region. This can be more effectively exhibited.

According to a seventeenth aspect of the present invention, in the contact lens according to any one of the first to fifteenth aspects, the pair of first power regions are elliptical regions.

In the contact lens of this aspect, for example, the outer diameter size in each direction during wearing can be made relatively different in the first power region. Therefore, for example, by increasing the outer diameter dimension of the first power region in the left-right direction rather than the up-down direction, even if there is a large individual difference in the amount of lateral deviation of the pupil center relative to the lens geometric center during wearing It becomes possible to make it possible to cope.

An eighteenth aspect of the present invention is the contact lens according to any one of the first to seventeenth aspects, wherein the first power region and the second power region are between the first power region and the first power region. A transition region in which the lens power between the lens power in the power region and the lens power in the second power region is set is provided.

In the contact lens of this aspect, the quality of appearance in the intermediate region of the viewing distance targeted for tuning in the first power region and the second power region can be improved by the optical characteristics of the transition region. Further, by providing the transition region, it is possible to reduce the deterioration in the quality of the appearance caused by the optical adverse effect at the boundary portion between the first power region and the second power region. In this transition area, the intermediate lens power between the first power area and the second power area is preferably set, for example, in any of the following nineteenth to twenty-first aspects.

A nineteenth aspect of the present invention is the contact lens according to the eighteenth aspect, wherein in the transition region, the lens power in the first power region is changed to the lens power in the second power region. The lens power that gradually changes is set to have a progressive structure.

A twentieth aspect of the present invention is the contact lens according to the eighteenth aspect, wherein in the transition region, the lens power in the first power region is changed to the lens power in the second power region. Thus, a multi-focal structure is formed by setting a plurality of lens power levels that change step by step.

A twenty-first aspect of the present invention is the contact lens according to the eighteenth aspect, wherein a constant lens power is set throughout the transition region.

In the present invention, a mode in which at least one of the lens powers set in the first power region and the second power region gradually changes is also adopted. That is, according to a twenty-second aspect of the present invention, in the contact lens according to any one of the first to twenty-first aspects, the lens power in the first power region and the lens power in the second power region. In at least one of the above, a lens power that gradually changes is set, and the optical region has a progressive structure.

According to a twenty-third aspect of the present invention, in the contact lens according to any one of the eighteenth to twenty-first aspects, between the pair of first power regions provided apart from each other, The transition region is provided, and the pair of first power regions are positioned in a connected state via the transition region.

In the contact lens of this aspect, since the transition region is provided over the entire circumference on the outer peripheral side of the first power region, the effect of improving the appearance quality as described above due to the optical characteristics of the transition region is further advantageous. To be able to get to.

According to a twenty-fourth aspect of the present invention, in the contact lens according to any one of the first to twenty-third aspects, the pair of first power regions has the second power over the entire circumference. The second power region is also provided between the pair of first power regions that are surrounded by a region and are spaced apart from each other.

In the contact lens of this aspect, since the second power region is provided over the entire circumference on the outer periphery side of the first power region, not only the first power region but also the optical characteristics of the second power region. It is possible to further improve the quality of the appearance.

According to a twenty-fifth aspect of the present invention, in the contact lens according to any one of the first to twenty-fourth aspects, a lens power for correcting astigmatism is provided to form a toric lens.

The contact lens in the present invention is not limited to a contact lens that corrects only presbyopia, and may be employed as, for example, a toric lens for presbyopia provided with a lens power for correcting astigmatism.

In the contact lens having the structure according to the present invention, a pair of symmetrically provided paired lenses even in a wearing state in which the lens geometric center is worn on either of the left and right eyes and the lens geometric center is deviated on either side of the pupil center. Any of the first power regions can be set at substantially the same position as the pupil center. Therefore, it is not necessary to distinguish between left and right when setting the first power region to be deviated from the lens geometric center in consideration of the deviation of the lens geometric center from the pupil center in the wearing state. As a result, it is not necessary to separately manufacture and manage the left eye and right eye separately, and there is no need for a mark or the like indicating the direction of deviation of the optical center. It is possible to effectively enjoy the excellent optical characteristics exhibited by the first power region deviated and set with respect to the lens geometric center in advance and the second power region on the outer periphery thereof. .

BRIEF DESCRIPTION OF THE DRAWINGS Front explanatory drawing which shows the contact lens as 1st embodiment of this invention. II-II sectional drawing in FIG. The graph which shows an example of the lens power set to the optical area | region of the contact lens shown by FIG. It is a graph which shows another example of the lens power set to the optical area | region of the contact lens shown by FIG. 1, (a) WHEREIN: The lens power in a transition part is made constant, (b) WHEREIN: The lens in a transition part The frequency is changing step by step. It is a graph which shows another example of the lens power set to the optical area | region of the contact lens shown by FIG. 1, In (a), the lens power of the 1st power area and the 2nd power area is made constant. In (b), the lens power is changed in consideration of the spherical aberration of the lens power in the first power region and the second power region. In (c), the lens power is gradually stepless in the optical region. It has changed. Front explanatory drawing which shows the contact lens as 2nd embodiment of this invention. It is a graph which shows an example of the lens power set to the optical area | region of the contact lens shown by FIG. 6, The lens power of the 1st power area and the 2nd power area is made constant in (a), In (b), the lens power changes in a stepless manner in the optical region. Front explanatory drawing which shows the contact lens as 3rd embodiment of this invention. Front explanatory drawing which shows the contact lens as 4th embodiment of this invention. Front explanatory drawing which shows the contact lens as 5th embodiment of this invention. Front explanatory drawing which shows the contact lens as 6th embodiment of this invention. Front explanatory drawing which shows the contact lens as 7th embodiment of this invention. Front explanatory drawing which shows the contact lens as 8th embodiment of this invention. Front explanatory drawing which shows the contact lens as 9th embodiment of this invention. XV-XV sectional drawing in FIG. Front explanatory drawing which shows the contact lens as 10th Embodiment of this invention.

Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show a contact lens 10 as a first embodiment of the present invention. This contact lens 10 has a circular outer periphery around the central axis passing through the lens geometric center 12 in the front view shown in FIG. 1, and has a substantially spherical crown shape as a whole. As is well known, the lens rear surface of the curved concave surface is worn on the surface of the cornea of the eyeball.

In addition, the contact lens 10 of this embodiment may be any of a hard type, a soft type, and a composite type, and the material is not limited at all. For example, the hard type can be applied to a contact lens made of an oxygen permeable material (RGP) made of a polymer material of a copolymer component such as a silicone-containing component and a lens forming monomer. Moreover, as a soft type, for example, it can be applied to a contact lens made of a non-hydrous material such as acrylic rubber or silicone in addition to a hydrous material such as PHEMA (polyhydroxyethyl methacrylate) or PVP (polyvinylpyrrolidone). . Further, the present invention can be applied to a composite type contact lens in which the hard type material and the soft type material are selectively used in the central portion and the outer peripheral portion, for example.

The contact lens 10 has a substantially circular optical region 14 in the central portion centered on the lens geometric center 12, and a substantially annular peripheral portion 16 is provided on the outer peripheral side of the optical region 14. Yes. Further, on the outer periphery of the peripheral portion 16, an edge portion 18 that smoothly connects the front and rear surfaces of the lens is formed in an annular shape. The optical region 14 has optical characteristics that exert an optical action on the eye optical system of the lens wearer, and a predetermined lens power is set. The peripheral portion 16 does not directly exert an optical action on the eye optical system, but has a predetermined inner and outer surface shape so as to satisfy lens stability on the cornea, wearing feeling, and the like.

The optical region 14 is provided with a first power region 20 and a second power region 22 in which different lens powers are set. The optical region 14 exhibits a simultaneous vision type correction action on the eye optical system by the first power region 20 and the second power region 22. A contact lens for correcting presbyopia is provided by providing optical characteristics corresponding to both vision and distance vision.

Specifically, a pair of first power regions 20 that are circular in the front view of the lens shown in FIG. 1 are provided. The pair of first power regions 20 are formed with the same optical characteristics and shape. A pair of first power regions 20 and 20 are provided in line symmetry with respect to a symmetrical radial line 24 extending in the vertical direction in FIG. 1 through the lens geometric central axis 12.

In other words, the pair of first power regions 20 and 20 are set such that their outer centers 26 and 26 are separated from each other on both sides of the lens geometric center 12 by a deviation amount δ. The outer diameter dimension φR1 of the first power region 20 is 2δ ≧ R1, and in the present embodiment, 2δ> R1.

Furthermore, a transition portion 28 as a transition region is provided on the outer peripheral side of each first frequency region 20. In this transition portion 28, an intermediate lens power between the lens power in the first power area 20 and the lens power in the second power area 22 is set.

In the optical region 14, the outer peripheral region that extends so as to surround the pair of first power regions 20, 20 and the respective transition portions 28, 28 is the second power region 22.

In particular, in the present embodiment, the external centers 26 and 26 of the pair of first power regions 20 and 20 are set on an orthogonal radial line 30 that passes through the lens geometric center 12 and is orthogonal to the symmetrical radial line 24. . As a result, the optical characteristics set in the optical region 14 are line symmetric with respect to the symmetric diameter line 24 and are also line symmetric with respect to the orthogonal diameter line 30.

Moreover, in this embodiment, the transition part 28 is made into the annular | circular shape extended by the fixed radial direction width dimension B1 over the outer periphery of the 1st frequency area | region 20 over the perimeter. Furthermore, in the present embodiment, in the direction of the orthogonal diameter line 30, the pair of first power regions 20, 20 positioned with the symmetrical diameter line 24 interposed therebetween are provided apart from each other, and the separation distance L 1 is , L1> (2 × B1). Thereby, between the pair of first frequency regions 20 and 20, the transition portions 28 and 28 provided on the respective outer circumferences are located, and the second portion is located between the transition portions 28 and 28. A frequency region 22 is provided. In short, the transition portions 28, 28 and the second power region 22 are provided so as to surround the entire circumference on the outer periphery of each first power region 20, 20. , 28 and the second power region 22, the first power regions 20, 20 are located in a connected state.

Here, the outer diameter dimension φR1 of the first power region 20, the deviation amount δ of the outer center 26 with respect to the symmetric diameter line 24, the radial width dimension B1 of the transition portion 28, and the like take into account the wearing state of the contact lens 10. Is set. That is, under the wearing state, the contact lens 10 is biased toward the ear side on the cornea according to the surface shape of the cornea and the like, and the pupil center located on the optical center axis of the eye optical system is located in the cornea. The pupil center 32 is located with a deviation from the lens geometric center 12 of the contact lens 10, for example, by being biased to the nose side relative to the center.

Specifically, when FIG. 1 is viewed from the front side of the lens in the wearing state, when the right side is the nose side and the left side is the ear side, the center 32 of the pupil 34 is shifted to the right side with respect to the lens geometric center 12. Will be. In the contact lens 10 of the present embodiment, the distance corresponding to the shift amount of the pupil center 32 to the right side with respect to the lens geometric center 12 in this wearing state is the deviation amount of the first power region 20 with respect to the lens geometric center 12. It is set to δ. Therefore, the pair of first power regions 20 and 20 are biased to the opposite sides with respect to the symmetrical radial line 24 with such a deviation amount δ.

In short, FIG. 1 is set so that the deviation amount X between the pupil center 32 and the outer shape center 26 of the first power region 20 is substantially zero in the direction of the orthogonal diameter line 30 that is the left-right direction as viewed from the front in the wearing state. Is done. In the second and later embodiments described later, the illustration of the pupil 34, the pupil center 32, and the deviation amount X is omitted. Here, the deviation amount of the pupil center 32 in the wearing state in the direction of the orthogonal diameter line 30 from the lens geometric center 12 can be obtained, for example, statistically although there is a slight individual difference. Although there is a slight difference depending on the rear surface shape of the contact lens 10, the deviation amount δ of the first power region 20 with respect to the lens geometric center 12 is generally about 1 mm to 1.5 mm. Therefore, in the present embodiment, the value of δ is preferably set in the range of 0.3 mm ≦ δ ≦ 4.0 mm, and more preferably in the range of 0.8 mm ≦ δ ≦ 2.0 mm. Is done.

Further, in the assumed range of use of the contact lens 10, in the photopic vision in which the diameter dimension (pupil diameter) φA of the pupil 34 becomes small, many areas in the pupil 34 are occupied by one first frequency area 20. It is desirable. By setting the correction lens power for photopic vision in the first power region 20, it is possible to stably enjoy the visual acuity correction effect due to the optical characteristics of the first power region 20 in photopic vision. Preferably, 50% or more of the photopic pupil 34 is occupied by the first power region 20, and more preferably 70% or more of the pupil 34 is occupied by the first power region 20. Become.

On the other hand, in the scotopic vision where the pupil diameter φA increases in the assumed application range of the contact lens 10, substantially the entire first power region 20 is included in the pupil 34, and the transition portion 28 and the first The second power region 22 also occupies a predetermined region in the pupil 34. By setting the correction lens power for scotopic vision in the second power region 22, it is possible to stably enjoy the visual acuity correction effect due to the optical characteristics of the second power region 22 in scotopic vision. Preferably, more than 40% of the dark-sighted pupil 34 is represented by the second power region 22, and more preferably, 60% or more of the pupil 34 is occupied by the second power region 22. Become.

Also, it is desirable that the other first power region 20 does not substantially affect the first power region 20 even in dark places where the pupil diameter φA increases. Specifically, it is desirable that the size of the other first power region 20 included in the pupil 34 is 20% or less of the pupil 34 even in a dark place environment, and more preferably the pupil. 34% or less of 34.

In order to effectively obtain the optical characteristics of photopic and scotopic vision as described above, the outer diameter size φR1 of the first power region 20 is 1 in the general use environment based on the statistical information of the pupil diameter φA. It is desirable to determine within the range of 0.0 mm ≦ R1 ≦ 2.5 mm, and more preferably within the range of 1.2 mm ≦ R1 ≦ 2.0 mm. Further, the separation distance L (L1 in FIG. 1) of the pair of first power regions 20 and 20 in the direction of the orthogonal diameter line 30 is preferably 0.10 mm or more, and more preferably 0.30 mm or more. It is said. Thereby, one first power region 20 can be positioned on the pupil 34, and the influence on the quality of view (QOV) by the other first power region 20 can be substantially avoided. The separation distance L1 is desirably set according to the amount of deviation δ of the first power region 20 with respect to the lens geometric center 12 at the lens stable position in the wearing state. Specifically, when the other first frequency region 20 is not included in the pupil 34 even in dark place vision, the maximum value of the pupil diameter is set to φA ′ so that L1 + 2δ ≧ φA ′. The

Furthermore, in the contact lens 10 of the present embodiment, the intermediate lens power is set in the transition portion 28 provided between the first power region 20 and the second power region 22. For example, as shown in FIG. 3, a near lens power α (diopter) that is a vision correction power for near vision is set in the first power area 20, and a far distance in the second power area 22. Assuming that the distance lens power β (diopter), which is the visual acuity correction power, is set, the intermediate lens power γ (diopter) of the transition unit 28 is β <γ <α. Specifically, the intermediate lens power γ changes linearly and continuously from the near lens power α to the far lens power β.

However, the setting mode of the lens power in the transition unit 28 is not limited. For example, as described above, the entire transition portion 28 continuously connects the first power region 20 and the second power region 22 and substantially includes the first and second power regions 20 and 22. In addition to the bifocal contact lens 10 having the transition portion 28, it is possible to set the lens power as shown in FIG. 4 or FIG.

That is, in the lens power setting mode shown in FIG. 4A, a constant intermediate lens power γ is set for the entire transition portion 28. Thereby, the lens powers α, γ, and β that are constant in the respective regions are set in the first power region 20, the transition portion 28, and the second power region 22 in the contact lens 10. Specifically, when the lens power α of the first power area 20 is + 1.0D and the lens power β of the second power area 22 is −3.0D, the lens power γ of the transition unit 28 is −3. Within the range of 0D ≦ γ ≦ + 1.0D, for example, the lens power γ is set to −1.5D. As described above, the contact lens 10 is a contact lens having a multifocal structure including the transition portion 28 having a constant lens power.

4B is a lens power range from the lens power α in the first power area 20 to the lens power β in the second power area 22, and the transition power of the transition section 28 is as follows. The lens power γ is set so as to gradually change from the first power area 20 toward the second power area 22. In short, the intermediate lens power γ of the transition portion 28 differs from γ1, γ2,... By a predetermined width from the first power region 20 toward the second power region 22, and β <γ1 <γ2 <.・ <Α. Thereby, the transition portion 28 having different lens powers in a plurality of steps from the near lens power α provided in the first power area 20 to the distance lens power β provided in the second power area 22 is provided. In addition, the contact lens 10 having a multifocal structure is realized.

Further, in the lens power setting mode shown in FIG. 5A, the lens power range of the first power region 20 to the lens power β of the second power region 22 is changed. The lens power γ is set so as to gradually and continuously change from the first power area 20 toward the second power area 22. In short, the intermediate lens power γ of the transition portion 28 continuously changes from the first power region 20 toward the second power region 22. As a result, the lens power is gradually changed steplessly from the near lens power α provided in the first power area 20 to the distance lens power β provided in the second power area 22. A contact lens 10 with a structural transition 28 is realized.

Furthermore, in the contact lens 10 having the transition portion 28 having such a progressive structure, the lens power set in at least one of the first power region 20 and the second power region 22 has a spherical aberration of the lens power. It may be provided in consideration. That is, as shown in FIG. 5B, the lens power provided in the first power region 20 is set so as to gradually change from α ′ to α in a stepless manner, while the second power region. The lens power provided at 22 may be changed steplessly from β to β ′. Further, in the transition section 28, the intermediate lens power γ is gradually changed steplessly from the lens power α to β. From this, the contact lens 10 of FIG. 5B is a contact lens having a progressive structure that gradually changes in a stepless manner from the lens power α ′ to β ′ in the optical region 14. The lens power α ′ is a numerical value larger than α by a predetermined amount, and the lens power β ′ is a numerical value smaller than β by a predetermined amount.

That is, the lens power α set in the first power region 20 and the lens power β provided in the second power region do not need to be constant in each of these regions. In short, as shown in FIG. 5C, in the entire optical region 14, the lens power is set to the second power region 22 from the lens power α set to the first power region 20. Until the frequency β, it may be gradually changed steplessly without having a constant region. As described above, the contact lens 10 may gradually change at least one of the lens powers set in the first power region 20 and the second power region 22 steplessly, and the transition portion 28 has a progressive structure. In addition, the optical region 14 may have a progressive structure. As shown in FIGS. 5B and 5C, when the optical region 14 has a progressive structure, since the lens power changes smoothly and continuously, the boundary of the transition portion 28 is not clearly formed.

The difference between the lens power α of the first power area 20 and the lens power β of the second power area 22, that is, the added power to the second power area 22 provided in the first power area 20 is preferable. Is set in the range of +0.25 to +4.0 diopter, and more preferably in the range of +1.0 to +2.5 diopter. If it is covered and smaller than +0.25 diopter, the difference in appearance between the first power region 20 and the second power region 22 becomes excessively small. For example, the contact lens 10 of the present invention is used for presbyopia correction. When used as a contact lens, there is a possibility that the effect of correcting near vision or far vision or both cannot be sufficiently obtained. Further, if it is larger than +4.0 diopter, the difference in appearance between the first power region 20 and the second power region 22 becomes excessively large. For example, it is used when shifting from near vision to far vision. This is because the person may feel uncomfortable.

Furthermore, the contact lens 10 as described above employs circumferential positioning means 36 for positioning in the circumferential direction so that the symmetric diameter line 24 is substantially vertically up and down in the worn state.

As the circumferential positioning means 36, a conventionally known contact lens of the present invention is preferably used. Specific examples include the “truncation method” described in Japanese Utility Model Laid-Open No. 48-13048, the “prism ballast method” disclosed in Japanese Patent Application Laid-Open No. 11-258553, etc., and Japanese Patent Application Laid-Open No. 8-304745. The disclosed “slab-off method (double thin method)”, the “periballast method” disclosed in US Pat.

In other words, in the “truncation method”, the contact lens is positioned in the circumferential direction by using the lower end outer periphery of the lens as a contact edge extending linearly or in a curved shape with a small curvature in the chord direction, and supporting the contact edge with the lower eyelid To do. In the truncation method, by setting the outer periphery of the upper and lower ends of the lens as contact edges, stable positions in the lens circumferential direction can be given in two directions on the circumference that are the upside down positions.

The “prism ballast method” is a method of positioning the contact lens in the circumferential direction using the gravitational action by setting a prism on the entire lens and gradually increasing the thickness downward from the upper end.

In the slab-off method, a thin portion that is gradually thinned from an intermediate portion in the vertical direction toward the upper and lower sides in the peripheral portion located on the outer peripheral side of the optical region of the lens is provided, and the upper and lower portions of the lens are eroded by the eyelids. The contact lens is positioned in the circumferential direction by using the engraving action and the eyelid pressure action on the inclined surfaces of the upper and lower parts of the lens.

The “periballast method” is a method of forming a pair of thick parts with the positions of the centers of gravity slightly deviated downward on the left and right sides of the lens peripheral part, and using the weight balance of these pair of thick parts, Positioning in the circumferential direction.

Of the circumferential positioning means 36, in the contact lens 10 of the present embodiment, as shown in FIGS. 1 and 2, a pair of the peripheral portion 16 is located in a region positioned in the vertical direction in the worn state. The “slab-off method” in which the thin wall portions 38 and 38 are provided is employed. Each of the thin- walled portions 38 and 38 gives the peripheral portion 16 a shape that gradually reduces the lens thickness toward the outer sides on both sides in the vertical direction that is the direction of the symmetrical radial line 24. In this embodiment, each thin- walled portion 38, 38 has a line-symmetric shape with respect to the symmetric diameter line 24 and the orthogonal diameter line 30, that is, the peripheral portion 16 has a line-symmetric shape with respect to the symmetric diameter line 24 and the orthogonal diameter line 30. Has been. Therefore, in the present embodiment, the entire contact lens 10 has a line-symmetric shape with respect to the symmetrical diameter line 24 and the orthogonal diameter line 30.

In the present embodiment, the contact lens 10 can be stably positioned in the circumferential direction by providing the pair of thin portions 38, 38. That is, in addition to the balancing action due to the weight distribution in the circumferential direction of the contact lens 10, the contact lens 10 has a symmetrical radial line 24 that rises and falls in the wearing state due to the gripping action of the eyelids and the pushing action due to eyelid pressure. In the state extending in the direction, that is, in the state shown in FIG. In particular, the pair of thin portions 38, 38, which are the circumferential positioning means 36 of the present embodiment, are line symmetric with respect to the orthogonal diameter line 30, in other words, vertical line symmetry, and the symmetrical diameter line 24 of the contact lens 10 in the worn state. It is not distinguished which of the two ends of the direction is located above. The pair of thin portions 38 and 38 provide the contact lens 10 with a stable position in the lens circumferential direction in two directions on the circumference that is the upside down position. By such positioning in the circumferential direction so as to be stabilized at the circumferential position shown in FIG. 1 during wearing, either one of the pair of first power regions 20, 20 becomes the contact lens 10. It is aligned with the pupil center 32 of the wearing eye to be worn.

The contact lens 10 of the present invention having such a structure can exhibit the following effects. That is, since the optical region 14 composed of the pair of first power regions 20, 20, the second power region 22, and the transition portion 28 as a whole has a line symmetrical shape with respect to the symmetrical radial line 24, the contact lens 10 does not need to distinguish between left and right, and can be worn on either the left or right eye of the user. Thereby, the increase in the number of standards of the contact lens 10 can be suppressed, and the labor and cost of manufacture by the manufacturer and management by the seller can be significantly reduced. Further, the management of the contact lens 10 by the user is facilitated, and the storage space for the contact lens 10 can be reduced.

Furthermore, the outer shape centers 26 and 26 of the pair of first power regions 20 and 20 are also deviated from the lens geometric center 12 in accordance with the deviation amount of the pupil center 32 deviated from the corneal center. As a result, under the wearing state, the outer shape center 26 of one first power region 20 is made to substantially coincide with the pupil center 32, and a good quality of view (QOV) is effectively ensured. obtain.

Further, the contact lens 10 is provided with a circumferential positioning means 36, and for example, rotation of the contact lens 10 can be suppressed under the wearing state. Thereby, it is possible to prevent the outer shape center 26 of the first power region 20 from deviating from the pupil center 32, and it is possible to suppress a decrease in QOV and to maintain a good QOV.

In particular, the contact lens 10 of this embodiment can exhibit the following effects. That is, in this embodiment, the slab-off method is adopted as the circumferential direction positioning means 36. The contact lens 10 according to the present embodiment has a symmetrical shape with respect to the symmetric diameter line 24 and the orthogonal diameter line 30 as a whole, and therefore the contact lens 10 does not need to be distinguished not only on the right and left but also on the top and bottom. In addition, the increase in the number of standards can be suppressed more effectively. Further, the contact lens 10 can be easily manufactured without requiring the user to add printing or marking marks for determining the circumferential direction of the contact lens.

Furthermore, in the contact lens 10 of the present embodiment, the first power region 20 has a circular shape, which corresponds to the shape of the substantially circular pupil 34. Thereby, for example, even when the pupil diameter φA is reduced during photopic vision, it is possible to effectively secure a region where the first power region 20 and the pupil 34 overlap, and the first power The vision correction effect by the region 20 can be sufficiently exerted.

Further, in the present embodiment, since the pair of transition portions 28 are provided, a rapid change in the lens power is suppressed, and a good QOV can be obtained. In particular, in the present embodiment, each of the transition portions 28 is formed over the entire circumference on the outer circumference of the first frequency region 20. The pair of transition portions 28 and 28 are spaced apart from each other, and the second frequency region 22 is also provided between the pair of transition portions 28 and 28. Therefore, in the transition portion 28, a region overlapping with the pupil 34 can be sufficiently secured to improve the QOV, and at the time of transition between the first power region 20 and the second power region 22 Can be effectively reduced.

Next, FIG. 6 shows a contact lens 40 as a second embodiment of the present invention. The contact lens 40 according to the present embodiment has a shape in which the pair of transition portions 28 are not provided as compared with the contact lens 10 according to the first embodiment. In the following description, parts that are substantially the same as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted.

The contact lens 40 has a shape in which the outer periphery of the pair of first power regions 42 and 42 and the second power region 22 are directly connected by not providing the transition portion 28. Therefore, the diameter size of the first frequency region 42 of the present embodiment can be, for example, the outer diameter size of the transition portion 28 of the first embodiment, that is, φ (R1 + 2 × B1). In the form, it is possible to secure a first frequency area larger than that in the first embodiment. Alternatively, the area of the second power region 22 can be set large while maintaining the diameter of the first power region 42 at the same diameter as the first power region 20 in the first embodiment. .

Since the contact lens 40 of the present embodiment does not include a transition portion, the lens power as shown in FIGS. 7A and 7B is shown, for example. That is, in FIG. 7A, the lens power α ″ is set in the first power area 42 and the lens power β ″ is set in the second power area 22, while these lens powers α ″, The lens power in the middle of β ″ is not set. Thereby, the contact lens 40 of this embodiment can be made into the contact lens of the bifocal structure which does not have a transition part. Note that the lens power change in the case of a contact lens having a bifocal structure that does not include such a transition portion is such that the intermediate lens power set in the transition portion 28 shown in FIG. The lens power is substantially the same as the lens power or the lens power in the second power region. Alternatively, in FIG. 7B, the lens power α ″ is set in the first power area 42 and the lens power β ″ is set in the second power area 22. The lens power is gradually set steplessly from α ″ to β ″ over the second power region 22, that is, in the optical region 14. Thereby, the contact lens 40 of this embodiment can be made into the progressive contact lens which does not have a transition part. It should be noted that the lens power change in the case of a progressive structure contact lens not provided with such a transition portion is substantially substantially the same as the lens power change in the progressive structure contact lens provided with a transition portion shown in FIG. It is said.

The contact lens 40 of this embodiment having such a shape can exhibit the same effects as the contact lens 10 of the first embodiment, and can further exhibit the following effects. That is, since the first frequency region or the second frequency region, or both frequency regions can be secured in a larger range compared to the first embodiment, the first frequency region 42 or the second frequency region. 22, or the vision correction effect by both power regions 42 and 22 can be obtained more efficiently.

Next, FIG. 8 shows a contact lens 44 as a third embodiment of the present invention. In the contact lens 44 of the present embodiment, compared to the contact lens 10 of the first embodiment, the second power region 22 is between the pair of first power regions 20 and 20 and between the pair of transition portions 28 and 28. Is not provided, and the pair of transition portions 28, 28 are substantially in contact at one point on the outer periphery. In particular, in the present embodiment, a pair of transition portions 28 and 28 each having a substantially circular shape on the lens geometric center 12 where the symmetric diameter line 24 and the orthogonal diameter line 30 intersect each other are substantially in contact with each other at the outer peripheral edge portion. Has been.

That is, in the present embodiment, only the transition portions 28, 28 provided on the outer circumferences of the first power regions 20, 20 between the pair of first power regions 20, 20 on the orthogonal diameter line 30. Is provided. Therefore, when the separation distance between the pair of first power regions 20 and 20 on the orthogonal diameter line 30 is L2, and the radial width dimension of the transition portion 28 is B2, L2≈ (2 × B2).

Also in the contact lens 44 of this embodiment having such a shape, the same effect as that of the contact lens 10 of the first embodiment can be exhibited. That is, in the present invention, it is not always necessary to provide the second power region 22 between the pair of first transition portions, in other words, between the pair of first power regions on the orthogonal diameter line 30. Further, the pair of transition portions are not necessarily provided separately as in the first embodiment, and may be in contact with each other at the outer peripheral edge, for example.

Next, FIG. 9 shows a contact lens 46 as a fourth embodiment of the present invention. In the contact lens 46 of the present embodiment, the second power region 22 is provided between the pair of first power regions 20, 20, that is, between the pair of transition portions, as compared with the contact lens 10 of the first embodiment. Only a pair of transition portions 48, 48 are provided. Moreover, the connection part of a pair of transition parts 48 and 48 on the symmetrical diameter line 24 has predetermined length.

Specifically, the outer peripheral shape of each transition portion 48 of the present embodiment is a substantially notch circle shape cut into an arcuate shape having a symmetrical radial line 24 as a chord. The chords are in contact with each other on the symmetric diameter line 24, and the pair of transition portions 48, 48 are connected to each other to form a substantially bowl shape. ing. That is, in this embodiment, when the separation distance between the pair of first power regions 20 and 20 on the orthogonal diameter line 30 is L3, and the radial width dimension of the annular portion of the transition portion 48 is B3. , L3 <(2 × B3).

Also in the contact lens 46 of this embodiment having such a shape, the same effect as that of the contact lens 10 of the first embodiment can be exhibited. In other words, in the present invention, the pair of transition portions formed in an annular shape do not necessarily need to be separated or contacted at one point, and are formed as an integral transition portion having a continuous structure in which the pair of transition portions are continuous at a predetermined width. It may be.

Next, FIG. 10 shows a contact lens 50 as a fifth embodiment of the present invention. Compared with the contact lens 40 of the second embodiment, the contact lens 50 of the present embodiment has a shape in which the second power region 22 is not provided between the pair of first power regions 42, 42. Yes. In other words, the contact lens 50 according to the present embodiment has a shape in which the pair of transition portions 28 are not provided as compared with the contact lens 44 according to the third embodiment.

Specifically, in this embodiment, the transition portion 28 and the second power region 22 are not provided between the pair of first power regions 42 and 42 on the orthogonal diameter line 30. That is, each of the pair of first power regions 42 and 42 has a substantially circular shape, and is substantially in contact at one point on each outer periphery. In particular, in the present embodiment, a pair of first power regions 42 and 42 each having a substantially circular shape are substantially in contact with each other on the lens geometric center 12 where the symmetric diameter line 24 and the orthogonal diameter line 30 intersect. ing. That is, in the present embodiment, the separation distance L between the pair of first power regions 42, 42 is set to approximately zero.

In the contact lens 50 of this embodiment having such a shape, the same effects as those of the contact lens 40 of the second embodiment and the contact lens 44 of the third embodiment can be exhibited. That is, in the present invention, the pair of first power regions are not necessarily provided separately from each other, and even if the outer peripheries of the pair of first power regions are in direct contact with each other on the symmetrical radial line 24. good.

As is clear from the first to fifth embodiments, the distance L between the pair of first power regions on the orthogonal diameter line 30 is not limited in any way. For example, the cornea for each user The separation distance L can be set according to the deviation amount of the pupil center with respect to the center. That is, the contact lens of the present invention can set and select the separation distance L according to the characteristics such as the corneal shape and eyelid pressure for each user, thereby further improving the quality of view (QOV). Improvement can be achieved.

Next, FIG. 11 shows a contact lens 52 as a sixth embodiment of the present invention. In the contact lens 52, compared to the contact lens 10 of the first embodiment, the pair of first power regions 54 and 54 and the transition portions 56 provided on the outer circumferences of the first power regions 54 and 54, respectively. The outer shape is an irregular shape that is not circular, and in this embodiment, the outer shape is an ellipse.

Specifically, in the present embodiment, the long axis of the pair of first power regions 54 and 54 is located on the orthogonal radial line 30 while the short axis extends in the direction of the symmetric radial line 24. In addition, each transition portion 56, 56 has a shape corresponding to the first frequency region 54, 54, and therefore the major axis of each transition portion 56, 56 is located on the orthogonal diameter line 30. The minor axis extends in the direction of the symmetrical radial line 24.

The contact lens 52 of this embodiment having such a shape can exhibit the following effects in addition to the same effects as the contact lens 10 of the first embodiment. That is, for example, it is particularly advantageously used when the deviation amount δ of the pupil center 32 with respect to the lens geometric center 12 varies or changes for each user or due to a change in usage environment. For example, when providing such a deviation amount δ to different users, in addition to adjusting the separation distance L between the pair of first power regions as described above, the direction of the orthogonal radial line 30 as in this embodiment can be used. By adopting the first frequency region 54 having a larger size, it becomes possible to cope widely with differences in the deviation amount δ. And since the 1st frequency area | region 54 and the transition part 56 can cover the pupil 34 efficiently, the quality (QOV) of a favorable appearance can also be maintained.

In particular, when the deviation direction of the pupil center 32 with respect to the lens geometric center 12 is the direction of the orthogonal diameter line 30, the dimension in the direction of the orthogonal diameter line 30 is set as in the first power regions 54 and 54 of the present embodiment. It is preferable to enlarge it.

Next, FIG. 12 shows a contact lens 58 as a seventh embodiment of the present invention. In the contact lens 58 of the present embodiment, the short axes of the pair of first power regions 54 and 54 and the pair of transition portions 56 and 56 are orthogonal to each other as compared to the contact lens 52 of the sixth embodiment. While located on the upper side, the long axis extends in the direction of the symmetrical radial line 24.

The contact lens 58 of this embodiment having such a shape can exhibit the same effects as the contact lens 52 of the sixth embodiment. In particular, even when a sufficient amount of the separation distance L is required, such as when a transition portion or the second power region 22 is provided between the pair of first power regions 54, 54, the first power region A sufficient amount of separation distance L can be ensured by adopting the first power region 54 having a different shape with a reduced size in the direction of the orthogonal diameter line 30 as in the case of the vertically long ellipse of this embodiment. . Further, when the deviation direction of the pupil center 32 with respect to the lens geometric center 12 is to be taken into consideration even in the direction of the symmetric radial line 24, the symmetric radial line as in the first power regions 54 and 54 having a vertically long ellipse shape. It is desirable to employ irregularly shaped first frequency regions 54, 54 having dimensions in 24 directions increased.

Next, FIG. 13 shows a contact lens 60 as an eighth embodiment of the present invention. Compared with the contact lens 52 of the sixth embodiment, the contact lens 60 of the present embodiment has a long axis and a short axis of the pair of first power regions 54 and 54 and the pair of transition portions 56 and 56, respectively. The shape is inclined with respect to the symmetric diameter line 24 and the orthogonal diameter line 30. In FIG. 13, the major axis of the first frequency region 54 and the transition portion 56 on the nose side (right side in the figure) is provided with an inclination angle of approximately 45 degrees with the orthogonal diameter line 30.

Therefore, the optical region 14 of the contact lens 60 of the present embodiment is not line-symmetric with respect to the orthogonal diameter line 30. For this reason, the contact lens 60 of the present embodiment is provided with a circumferential positioning means 36 that prevents upside down. That is, the circumferential positioning means 36 causes any one end in the direction of the symmetric radial line 24 to be positioned above the contact lens 60 in the worn state. In the contact lens 60 of the present embodiment, the slab-off method is adopted as the circumferential positioning means 36 in the same manner as in the previous embodiment. However, the region of the thin portion 38 ′ below the wearing state is changed to the thin portion 38 above the wearing state. It is smaller than that. Due to such effects as the difference in weight distribution between the thin portions 38 and 38 ′, a stable position in the lens circumferential direction is given to the contact lens 60 in one direction on the circumference, and the contact lens 60 of this embodiment is shown in FIG. It can be circumferentially positioned as shown.

The contact lens 60 of this embodiment having such a shape can exhibit the same effect as the contact lens 52 of the sixth embodiment. In particular, when the deviation direction of the pupil center 32 with respect to the lens geometric center 12 is inclined with respect to the symmetric diameter line 24 and the orthogonal diameter line 30, the deviation direction and the major axis direction of the first power region 54 are It is preferable that the directions are substantially the same.

Next, FIGS. 14 and 15 show a contact lens 62 as a ninth embodiment of the present invention, and FIG. 16 shows a contact lens 63 as a tenth embodiment of the present invention. ing. Compared with the contact lens 10 of the first embodiment, the contact lenses 62 and 63 of both embodiments have a pair of first power regions 20 and 20 and a pair of transition portions 28 and 28 with respect to the orthogonal diameter line 30. Thus, the shape is biased in the direction of the symmetric radial line 24. The contact lens 63 according to the tenth embodiment is obtained by inverting the optical region 14 of the contact lens 62 according to the ninth embodiment upside down. In the contact lens 62, the biasing direction is the lower side of the wearing state. On the other hand, in the contact lens 63, the deflection direction is set to the upper side of the wearing state. Moreover, in FIG. 14 and FIG. 16, the separation distance L4 between a pair of 1st frequency area | regions 20 and 20 in the orthogonal diameter line 30 direction is made smaller than FIG.

Specifically, with the contact lens worn, the pupil center 32 deviates not only in the orthogonal diameter line 30 direction but also in the symmetric diameter line 24 direction with respect to the contact lens geometric center 12 due to the surface shape of the cornea and the like. There are things to do. In general, the pupil center 32 often deviates obliquely downward on the nose side (lower right direction in FIG. 14) with respect to the lens geometric center 12 and takes a stable position. Therefore, in the ninth embodiment, the pair of first power regions 20 and 20 are arranged with respect to the orthogonal radial line 30 according to the deviation amount ε of the pupil center 32 with respect to the lens geometric center 12 in the direction of the symmetrical radial line 24. And biased downward in the wearing state. On the other hand, the surface shape of the cornea or the like varies greatly between individuals, and there are many users who have a stable contact lens position above the cornea and users who are stable when the contact lens is slightly rotated in the circumferential direction. For such a contact lens user, the contact lens 63 according to the tenth embodiment is preferably employed.

Therefore, the optical region 14 of the contact lens 62 of the ninth embodiment and the contact lens 63 of the tenth embodiment is not line-symmetric with respect to the orthogonal diameter line 30. For this reason, the contact lenses 62 and 63 of both embodiments are provided with circumferential positioning means 36 for preventing the upside down. In other words, the circumferential positioning means 36 causes any one end in the direction of the symmetric radial line 24 to be positioned above the contact lenses 62 and 63 in the worn state. In the contact lenses 62 and 63 of both embodiments, a prism ballast method is adopted as the circumferential positioning means 36. In short, in the contact lens 62 of the ninth embodiment, as shown in FIG. 15, the contact lens 62 is gradually thickened from the upper wearing state to the lower wearing state. A positioning portion 64 that is relatively thin in the thick region is provided at the lower end of the thick region so that the contact lens 62 can be gripped by the lower eyelid. Due to the difference in the weight distribution of the contact lens 62 and the operation of the lower eyelid in the positioning portion 64, a stable position in the circumferential direction of the lens is given to the contact lens 62 in one direction on the circumference. The contact lens 62 can be circumferentially positioned in the state shown in FIG. In addition, since the shape of the peripheral part 16 in the contact lens 63 of the tenth embodiment is the same as that of the contact lens 62 of the ninth embodiment, illustration of a sectional view is omitted. That is, in the contact lens 63 of the tenth embodiment, the prism ballast method is adopted as the shape of the peripheral portion 16 like the contact lens 62 of the ninth embodiment, and the positioning portion 64 is provided at the lower end of the thick region. Is provided.

This makes it possible to more accurately match the outer shape center 26 of the first power region 20 with the pupil center 32 under the wearing state of the contact lens 62 or the contact lens 63. As a result, it is possible to more effectively and stably enjoy the optical characteristics of the first power region 20 and the optical characteristics of the second power region 22.

Note that the vertical displacement amount ε in the wearing state can also be set according to the user's personal measurement information, and preferably the wearer's pupil center 32 is relative to the center of the first power region 20. Similarly to the direction of the orthogonal diameter line 30, the direction of the symmetry diameter line 24 is set so as to substantially match. Preferably, the amount of deviation between the pupil center 32 and the outer shape center 26 of the first power region 20 is set to be 1 mm or less in the orthogonal radial line 30 direction and the symmetric radial line 24 direction, more preferably It is set to be 0.5 mm or less.

Here, the deviation amount of the pupil center 32 in the wearing state in the direction of the symmetric radial line 24 from the lens geometric center 12 can be obtained, for example, statistically although there are slight individual differences. Although there is a slight difference depending on the rear surface shape of the contact lens 10, it is generally desirable that the deviation amount ε of the first power region 20 with respect to the lens geometric center 12 is set to 0.2 mm to 2 mm.

As mentioned above, although embodiment of this invention has been explained in full detail, this invention is not limited by the specific description. For example, the lens power of the optical region 14 can be set in consideration of the living conditions of the contact lens user. That is, for example, a lens power β for correcting far vision can be set in the first power areas 20, 42, 54, and a lens power α for correcting near vision can be set in the second power area 22. It is. In such a case, the lens power α is preferably set to an additional power in the range of +0.25 to +4.0 diopters with respect to the lens power β, and more preferably, the additional power is +1.0 to It is set in the range of +2.5 diopters.

Further, in the transition portions 28, 48, and 56, the lens power α of the first power region 20, 42, and 54 and the lens power β of the second power region 22 can be alternately provided in each annular shape in the radial direction. It is. Furthermore, in the transition portions 28, 48, 56, at least one of the lens power α of the first power region 20, 42, 54 and the lens power β of the second power region 22, and a lens power γ intermediate between them. It is also possible to provide each in an annular shape alternately in the radial direction. In this way, it is possible to adjust and set the appearance by appropriately tuning the lens powers of the transition portions 28, 48, and 56.

Further, in the fourth embodiment, the transition portions 48 are formed in an integral shape in which the outer circumferences of the pair of transition portions that are partially annular are continuous with a predetermined length on the symmetrical radial line 24. However, the second power region 22 extending vertically may be formed with a predetermined width so as to divide the transition portions 48, 48 on the symmetrical radial line 24. As described above, even when the pair of transition portions are separated from or in contact with each other, the outer shapes of the pair of transition portions are not limited to the circular shape or the elliptical shape as in the above-described embodiment.

Furthermore, the pair of first power regions is not limited to the circular shape or the elliptical shape as in the above embodiment. The shape of the outer shape of the pair of first power regions and the pair of transition portions may be, for example, a polygonal shape. Further, the width dimension of the transition portion formed around the first power region may be different in the circumferential direction. For example, one outer shape of the first power region and the transition portion is made circular and the other contour is formed. Can be an irregular shape such as an ellipse.

In addition, the contact lens of the embodiment may be employed as a contact lens for correcting presbyopia, for example, but a lens power for correcting astigmatism may be provided in the optical region 14. That is, the contact lens of the present invention can be employed as a toric lens for presbyopia capable of correcting astigmatism in addition to correcting presbyopia.

In the optical region 14, the radius of curvature for imparting desired optical characteristics to the contact lens may be set on both the front surface of the lens, the rear surface of the lens, or the front and rear surfaces of the lens. For example, while the lens rear surface is a spherical crown-shaped base curve with a predetermined radius of curvature, the radius of curvature that achieves the required lens power in the first power region and the second power region with respect to the lens front surface, respectively. Can be set. In addition, after setting the lens front and back surfaces that achieve the required lens power in the second power region in the entire optical region 14, in the first power region, the surface shape of either the lens front surface or the lens rear surface is set. It is also possible to realize the required lens power in the first power range by making it different. Furthermore, the cylindrical lens power is in any surface of the lens front surface and the lens rear surface in the optical region 14 in which the lens front and rear surface shapes that achieve the required lens power are set in the first power region and the second power region, respectively. It is also possible to set.

10, 40, 44, 46, 50, 52, 58, 60, 62, 63: contact lens, 14: optical region, 20, 42, 54: first power region, 22: second power region, 24: Symmetric diameter line, 28, 48, 56: Transition part, 30: Orthogonal diameter line, 32: Pupil center, 36: Circumferential direction positioning means, 38: Thin part, 64: Positioning part

Claims (25)

1. In the contact lens provided with the first power region and the second power region in which different lens powers are set in the optical region located in the center portion of the lens,
   A pair of the first power regions are provided symmetrically with respect to a symmetrical radial line that is one lens radial direction line, and the second power region is provided on the outer peripheral side of the pair of first power regions. The optical region is axisymmetric with respect to the symmetrical radial line, and
   A stable position in the lens circumferential direction so that the symmetrical diameter line extends in the vertical direction of the wearing eye and one of the pair of first power regions is aligned with the pupil center of the wearing eye in the wearing state. A contact lens, characterized in that it is provided with circumferential positioning means.
2. The contact lens according to claim 1, wherein the first power region has a vision correction power for near vision, while the second power region has a vision correction power for distance vision.
3. The contact lens according to claim 1, wherein the first power region has a vision correction power for distance vision, while the second power region has a power correction power for near vision.
4. The contact lens according to claim 1, wherein the first power region has a vision correction power for photopic vision while the second power region has a power correction power for scotopic vision.
5. 3. The contact lens according to claim 2, wherein the first power region has an added power of +0.25 to +4.0 diopters with respect to the second power region.
6. The contact lens according to claim 3, wherein the second power region has an added power of +0.25 to +4.0 diopters with respect to the first power region.
7. The contact lens according to any one of claims 1 to 6, wherein the entire lens has a line-symmetric shape with respect to the symmetrical radial line.
8. The contact lens according to any one of claims 1 to 7, wherein the optical region is line symmetric with respect to an orthogonal diameter line orthogonal to the symmetry diameter line.
9. The circumferential positioning means provides a stable position in the lens circumferential direction in two directions on the circumference, which is the upside down position, regardless of which of the opposite ends of the symmetric radial direction is located in the worn state. The contact lens according to claim 8.
10. The lens according to any one of claims 1 to 8, wherein the circumferential positioning means provides a stable position in the lens circumferential direction in one direction on the circumference so that a specific end in the symmetric radial direction is positioned upward in a worn state. The contact lens of any one of items.
11. The optical region is asymmetric with respect to the orthogonal diameter line by providing the pair of first power areas in a biased manner on either side of the both side areas partitioned by the orthogonal diameter line orthogonal to the symmetrical diameter line. And
    The circumferential positioning means provides a stable position in the circumferential direction of the lens in one circumferential direction so that a specific end in the symmetric radial direction is positioned upward in a worn state. The contact lens of any one of items.
12. The contact lens according to any one of claims 1 to 11, wherein the pair of first power regions are provided apart from each other.
13. In the pair of first power regions provided apart from each other, the influence of the other first power region on the first power region positioned on the pupil center in the wearing state The distance between the pair of first power regions is set according to the amount of deviation of the pupil center with respect to the lens stable position in the wearing state so that the lens is substantially avoided. The contact lens described.
14. The pair of first power regions are biased to opposite sides with respect to the symmetric diameter line with a deviation amount of 0.3 to 4.0 mm with respect to the symmetric diameter line. The contact lens of Claim 1.
15. The contact lens according to any one of claims 1 to 14, wherein the first power region has an outer diameter of 1.0 to 2.5 mm.
16. The contact lens according to any one of claims 1 to 15, wherein the pair of first power regions are circular regions.
17. The contact lens according to any one of claims 1 to 15, wherein the pair of first power regions are elliptical regions.
18. A transition region in which a lens power between the lens power of the first power region and the lens power of the second power region is set between the first power region and the second power region. The contact lens according to claim 1, wherein a contact lens is provided.
19. In the transition region, a lens power that gradually changes from the lens power of the first power region toward the lens power of the second power region is set, and the transition region has a progressive structure. The contact lens according to 18.
20. The multi-focal structure has a multi-focal structure in which, in the transition region, a plurality of lens powers that change stepwise from the lens power in the first power region toward the lens power in the second power region are set. The contact lens according to 18.
21. The contact lens according to claim 18, wherein a constant lens power is set throughout the transition region.
22. A lens power that gradually changes is set in at least one of the lens power in the first power region and the lens power in the second power region, and the optical region has a progressive structure. The contact lens according to any one of the above.
23. The transition region is provided between the pair of first power regions spaced apart from each other, and the pair of first power regions are positioned in a connected state via the transition region. The contact lens according to any one of claims 18 to 21.
24. Each of the pair of first power regions is surrounded by the second power region over the entire circumference, and the second power region is also provided between the pair of first power regions spaced apart from each other. The contact lens according to any one of claims 1 to 23, wherein a power region is provided.
25. The contact lens according to any one of claims 1 to 24, wherein a toric lens is provided with a lens power for correcting astigmatism.

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