WO2015060211A1

WO2015060211A1 - Contact lens

Info

Publication number: WO2015060211A1
Application number: PCT/JP2014/077680
Authority: WO
Inventors: 裕也本山; 坂田　博行; 貴志後藤; 征宏小島; 圭介山本
Original assignee: 株式会社メニコン
Priority date: 2013-10-21
Filing date: 2014-10-17
Publication date: 2015-04-30
Also published as: JPWO2015060211A1

Abstract

Provided is a contact lens with a novel structure that has improved wearing sensation through a reduction in scary emotions when being worn even by beginners and children, for example, inexperienced with contact lenses and facilitation of lacrimal fluid exchange, and that further assures hygienic aspects, thereby achieving excellent wearability. The contact lenses are a soft type formed from a flexible material and are a disposable type with the usage limit set for a period of three months or less. The lens outside dimensions are set within a range of 10 - 13.5 mm, and the diameter dimension for an optical part (14) is set at 0.6 or greater of the lens outside dimensions.

Description

contact lens

The present invention relates to a contact lens, and more particularly to a contact lens that can be suitably used even for beginners who use a contact lens for the first time or have just used it.

Conventionally, contact lenses described in, for example, Japanese Patent Application Laid-Open No. 10-161070 (Patent Document 1) have been used for correcting vision such as myopia, hyperopia and astigmatism. When wearing a contact lens, generally hold the upper and lower eyelids with one hand and keep your eyes wide open, while holding the lens placed on the finger of the other hand close to your eyes. It is made to adhere and hold on the cornea by surface tension etc. by superimposing on the cornea surface. Also widely adopted is a method of putting the lens on the tip of one finger, pulling the lower eyelid with the other finger, and pulling the upper eyelid with the other hand to bring the lens closer to the eye Has been.

By the way, for those who are using contact lenses for the first time, and for beginners who have just begun using them, putting foreign objects in their eyes is fearful and sometimes takes time to wear them. In particular, in recent years, the age of contact lens users has been declining, and there are many cases where the age of first use of contact lenses is a child of about 10 to 15 years old. In many cases, I felt enthusiastic and reluctant to use contact lenses. In addition, excessive nervousness from fear causes a tendency to become hypersensitive to foreign objects when wearing contact lenses, especially when the lens surface dries or the corneal surface of the lens increases. There was also a tendency to complain about a large foreign body.

However, the current situation is that no measures have been taken against the fear of users or excessive nervous responses when wearing contact lenses. No special contact lenses were taken into account.

In addition, contact lenses are worn directly in contact with corneal cells, and propagation of various bacteria tends to cause eye diseases. In addition, contact lenses are easy to accumulate due to adhesion of dirt such as lipids and proteins by being exposed to tears in a worn state. Therefore, it is important to be managed hygienically by regular scrubbing.

However, for contact lens beginners and children, maintenance such as scrubbing tends to be insufficient due to unfamiliarity and miscellaneous handling. For this reason, there is a problem that dirt adherence and propagation of various bacteria are likely to occur, and there is a high possibility that hygiene cannot be ensured.

JP-A-10-161070

The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is that the fear of wearing and the feeling of foreign matters during wearing are reduced, and the hygiene is easily ensured. Thus, for example, it is an object of the present invention to provide a contact lens having a novel structure that is easy to use for contact lens beginners and children.

Hereinafter, embodiments of the present invention made to solve such 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.

The first aspect of the present invention is a contact lens provided with a peripheral portion in the outer peripheral region of the optical portion in the central region and worn by being superimposed on the eye, and is a soft type made of a flexible material, It is a disposable type with a short-term expiration date set within 3 months, the lens outer diameter is set within the range of 10 to 13.5 mm, and the diameter of the optical part relative to the lens outer diameter Is set to 0.6 or more.

The contact lens structured according to the present invention is a disposable soft contact lens having a small outer diameter of 10 to 13.5 mm and a large optical part diameter ratio of 0.6 or more (optical part diameter / lens outer diameter). One of the major features of the configuration is that they are combined with each other. And, by combining such a special configuration, for example, a new contact lens that is easy to use even for contact lens beginners and children can be effectively realized.

In other words, the present inventor has conducted many experiments and researches on reducing the fear of a contact lens beginner and the like and the extraneousness caused by the excessive nervousness. I came to know that it would be effective. Covering and reducing the outer diameter of the lens can alleviate the fear of the first impression, and by reducing the outer diameter of the lens, the movement of the lens on the cornea during wearing is positive. This is because it is permitted and tear fluid exchange accompanying the movement of the lens is promoted, and the lens surface is prevented from drying and adsorbing to the corneal surface of the lens, thereby reducing the feeling of foreign matter.

Here, in the conventional general soft contact lens, the contact lens has a relatively large outer diameter of about 14 mm, thereby improving the positional stability on the cornea during wearing, so that the central portion can be improved. It is fundamental to stabilize the appearance through an optical unit that is provided and has optical characteristics with respect to the eye optical system. On the other hand, when the lens outer diameter size is reduced as described above, there is a concern that the stability of the appearance is lowered as the movement on the cornea increases. Therefore, the present inventor has conducted research on the assumption that such a problem can be avoided by increasing the ratio of the optical part outer diameter to the lens outer diameter, and the optical part diameter ratio is set to 0.6 or more. As a result, while maintaining a large amount of movement on the cornea with a small-diameter lens, it was possible to suppress deterioration in the quality of appearance and maintain a good QOV.

Therefore, in the contact lens structured according to the present invention, the soft type and the small diameter can not only reduce the visual fear of the first impression, but also the specific outer diameter size and the specific optical value. By adopting a combination of the diameter ratios, it was possible to achieve both the excellent wearing feeling accompanying the promotion of tear fluid exchange and the securing of good QOV. Therefore, for example, the feeling of foreign matter due to excessive nervousness in a contact lens beginner or the like can be reduced while ensuring a good appearance.

Furthermore, in the contact lens having the structure according to the present invention, the adhesion of dirt and the propagation of various germs during use are suppressed, and it is easy to ensure hygiene. That is, in the contact lens of the present invention, since the outer diameter of the lens is reduced as described above, a large amount of movement on the cornea in the wearing state is secured and tear fluid exchange is promoted. Emission of waste products in the eye due to can be promoted.

In addition, since the contact lens of the present invention has a small diameter, even a novice beginner or a child with small fingers can reduce the amount of washing remaining on the outer periphery of the lens and efficiently rub the entire lens surface. Improvement of hygiene management maintenance can also be expected. In addition, the contact lens of the present invention is a disposable type with a short-term expiration date set within 3 months, so it can be used for scrubbing and hygiene management by discarding it at the expiration date and replacing it with a new lens. Even inexperienced lens beginners can avoid the occurrence of significant problems in terms of hygiene.

Further, as another effect of the contact lens of the present invention, it can be mentioned that a wide range of conformity of the wearer's corneal curvature radius can be secured with respect to the curvature radius of the base curve attached to the rear surface of the optical unit. That is, the contact lens is worn while being attached to the corneal surface using the surface tension of tears, etc., but the curvature radius of the base curve is too small compared to the curvature radius of the corneal surface. On the cornea, the lens is adsorbed in a sucker shape, so that it is difficult to secure sufficient tear exchange, and the wearing feeling may be reduced. On the other hand, if the curvature radius of the base curve is too large compared to the curvature radius of the corneal surface, it is difficult to obtain the positional stability of the lens on the cornea, which may hinder the appearance and wearing feeling.

Here, in the contact lens having the structure according to the present invention, since the lens outer diameter is small, the lens adsorption force to the cornea based on the surface tension of tears can be set to be relatively small. Therefore, even when the radius of curvature of the base curve of the lens is sufficiently smaller than the radius of curvature of the corneal surface, the adsorption force of the lens to the cornea is suppressed and the amount of movement of the lens on the cornea is appropriately secured. It becomes possible.

On the other hand, even when the radius of curvature of the base curve of the lens is larger than the radius of curvature of the corneal surface, the outer diameter of the lens is small. The force can be kept small. Moreover, even if the lens is relatively large and moves on the cornea, a good appearance can be maintained by increasing the ratio of the optical portion to the lens outer diameter.

As described above, in the contact lens having a structure according to the present invention, it is possible to set a wider range of conformity of the wearer's corneal curvature radius to the curvature radius of the base curve attached to the rear surface of the optical unit. . And when such a compatible range is set wide, it becomes possible to reduce the number of standard lenses to be manufactured or reduce the types of lenses to be prepared in advance in the contact lens manufacturer or provider. Therefore, it is possible to efficiently provide suitable contact lenses to many lens users having different curvature radii.

According to a second aspect of the present invention, in the contact lens according to the first aspect, the radius of curvature of the corneal curvature Y of the wearer exceeds the curvature radius X of the base curve attached to the rear surface of the optical unit. The upper limit can be set.

In conventional contact lenses with a relatively large diameter, if the radius of curvature of the base curve of the lens is smaller than the radius of curvature of the cornea, it acts like a suction cup when worn and the adsorption force is excessive, ensuring sufficient tear exchange. Since it is difficult to do this, generally, the fitting range is set on condition that the radius of curvature of the wearer's cornea does not exceed the radius of curvature of the base curve of the lens. On the other hand, in the contact lens according to this aspect, as described above, the lens outer diameter size is reduced and the lens attracting force on the cornea is suppressed. Therefore, the contact lens exceeds the radius of curvature of the lens base curve. It is possible to set the upper limit of the radius of curvature of the cornea (the upper limit of the range of conformity of the lens to the cornea), thereby making it a suitable contact for many lens users with different corneal curvature radii. It becomes possible to provide a lens efficiently.

It should be noted that the range of the state of conformity of the contact lens to the cornea refers to what the contact lens provider presented to the user with no adverse effect on the appearance and wearing feeling. For example, with the average value of the lens movement amount Δ in the blink of an eye as an index, a state in which the movement amount falls within a predetermined range (specifically, 0 <Δ <1 mm or the like) It is also possible to specify objectively.

Further, in this embodiment, the lower limit of the range of conformity of the contact lens to the cornea is not particularly limited, but as described above, in the contact lens according to the present invention in which the lens outer diameter is small and the optical system ratio is large. Since the appearance when the lens is moved is advantageously ensured, the lower limit value of the corneal curvature radius that matches the curvature radius of the base curve can be made sufficiently small. Specifically, for example, it may be possible to set the radius of curvature of the base curve to -0.7 mm or less or -0.8 mm or less. It may also be possible.

According to a third aspect of the present invention, in the contact lens according to the first or second aspect, a lower limit and an upper limit of a fitting range of the wearer's corneal curvature radius Y are set on the rear surface of the optical unit. The radius of curvature X is set to be smaller and larger than the radius of curvature X, and the matching range between the upper limit and the lower limit can be set in a range exceeding 0.65 mm.

According to the present aspect, as described above, by setting the matching range of the curvature radius of the base curve with respect to the curvature radius of the cornea surface to a sufficiently wide range as compared with the contact lens having the conventional structure, as described above, A contact lens suitable for many lens users can be provided more efficiently by reducing the number of standards and the number of stocks.

According to a fourth aspect of the present invention, there is provided the contact lens according to any one of the first to third aspects, wherein the curvature radius of the base curve attached to the rear surface of the optical unit is X, and at least the curvature radius is X + 0. The amount of movement associated with blinking when worn on a 0.01 mm cornea is greater than 0 mm.

According to this aspect, the range of the radius of curvature of the cornea that matches the radius of curvature of the base curve can be set appropriately. In particular, in the present invention, the lens outer diameter is a relatively small diameter of 13.5 mm or less. And the value of the diameter (D _oz ) of the optical part (D _oz / DIA) with respect to the lens outer diameter (DIA) is set to 0.6 or more, so it conforms to the radius of curvature of the base curve. A large range of the radius of curvature of the cornea can be secured. In addition, the reason for the good adaptation to the radius of curvature of the cornea, which is larger than the base curve, is that the DIA is set to a small value, so that the adsorption area to the cornea and hence the adsorption force is suppressed, and the lens does not move on the cornea This is considered to be based on the fact that this is avoided.

A fifth aspect of the present invention is the contact lens according to any one of the first to fourth aspects, wherein the range of corneal curvature is greater than 0 mm and less than 1 mm with a blinking amount under wearing conditions. Exists in excess of 0.65 mm.

According to this aspect, it is possible to ensure a wide range of the curvature radius of the cornea that matches the curvature radius of the base curve. In particular, in the present invention, the lens outer diameter is a relatively small diameter of 13.5 mm or less. In addition, since the value (D _oz / DIA) of the optical part diameter dimension (D _oz ) with respect to the lens outer diameter dimension (DIA) is set to 0.6 or more, it conforms to the curvature radius of the base curve. A large range of the radius of curvature of the cornea can be ensured. In addition, the reason for showing good compatibility with small corneal curvature radii is that D _oz / DIA is large, the radial width dimension of the peripheral part itself is small, and the lift amount from the peripheral part to the edge part is also set small. Therefore, it is considered that the floating due to the flow of tears and the eyelids being caught on the edge portion are suppressed, and the loose state where the lens moves too much on the cornea is avoided.

As described above, in the present invention, the disposable soft contact lens newly adopts a characteristic configuration such as adopting a combination of a small outer diameter size in a specific range and a large optical part diameter ratio in a specific range. In addition to the visual dispelling effect of the first impression due to the small diameter, the wearing feeling is improved by promoting tear fluid exchange while ensuring the quality of appearance, and further improving hygiene As a result, a new contact lens that is easy to use, for example, for beginners and children of contact lenses can be effectively realized.

The front view of the contact lens as one embodiment of the present invention. Explanatory drawing which shows the II-II cross section and the cornea surface of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, FIG. 1 and FIG. 2 show a contact lens 10 as an embodiment of the present invention. The contact lens 10 has a spherical crown shape as a whole, and is worn by being superimposed on the surface of the cornea C of the eyeball shown in FIG. 2 as well known. Wearing means using a contact lens superimposed on the cornea of the human eye.

More specifically, the contact lens 10 of the present embodiment is a soft type contact lens and is formed of a soft material with high water content. As the soft material, conventionally known materials for various soft contact lenses can be used. For example, 2-hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA), N, N-dimethylacrylamide (DMAA), 1 Contains a hydrophilic monomer such as methyl-3-methylene-2-pyrrolidinone (MMP) and N-vinylpyrrolidone (N-VP), and a silicone compound such as tris (trimethylsilokine) silylpropyl methacrylate (TRIS), and is crosslinked As the agent, for example, ethylene glycol dimethacrylate (EDMA) and as the polymerization initiator, for example, those using 2-hydroxy-2-methyl-1-phenylpropan-1-one (HMPPO), etc. can be suitably employed.

The contact lens 10 has a lens center axis 12 as an optical axis, and has a substantially rotationally symmetric shape around the lens center axis 12. Further, the contact lens 10 has a substantially circular shape centered on the lens central axis 12 in a front view (axial view) shown in FIG.

Here, the lens outer diameter (DIA) of the contact lens 10 is set in the range of 10.0 to 13.5 mm, more preferably 11.0 mm to 13.5 mm.

If the lens outer diameter (DIA) is smaller than 10.0 mm, the amount of movement with respect to the cornea during wearing may be too large, or the area of the optical unit 14 to be described later may not be sufficiently secured, and the contact lens 10 will be small. This is because the handleability may be reduced.

On the other hand, when the lens outer diameter dimension (DIA) is larger than 13.5 mm, the contact lens 10 becomes large, and it is easy to give fear of wearing to the beginner of the contact lens. That is, the lens outer diameter (DIA) of the contact lens 10 according to the present invention is smaller than 13.8 mm, which is the minimum lens outer diameter (DIA) of a disposable soft contact lens that is generally widely used. Is set.

Further, an optical zone 14 having an appropriate lens power for correcting vision is formed in the central area of the contact lens 10. The optical unit 14 has a substantially circular shape centered on the lens central axis 12 in the front view (viewed in the axial direction) shown in FIG. Further, in the contact lens 10, a substantially annular peripheral portion 16 is formed in an outer peripheral region surrounding the optical portion 14 over the entire circumference. The peripheral portion 16 can be given various conventionally known shapes as required, and may be formed with an edge lift, for example. Further, an edge portion 17 that connects the front and rear surfaces of the lens is provided on the outer peripheral edge portion of the peripheral portion 16.

The optical unit 14 is a region that exerts an optical action on the human eye optical system in a worn state, and the size is set in consideration of an assumed pupil diameter and the like. The diameter dimension: D _oz is set to 0.6 or more with respect to the lens outer diameter dimension (DIA). Thereby, even if the lens outer diameter dimension (DIA) is reduced and the amount of movement on the cornea is increased, the area of the optical unit 14 can be effectively secured and the appearance can be stabilized.

It should be noted that the outer peripheral edge portion of the optical unit 14, in other words, the boundary with the peripheral portion 16 can be generally regarded as a change point of curvature on the longitudinal section on the front surface of the lens and the rear surface of the lens. However, for example, when the lens surface of the optical unit 14 is designed with a longitudinal cross-sectional shape that gradually changes in the radial direction, or the boundary is formed with a predetermined width in the radial direction and the optical unit 14 and the periphery between the lens front and rear surfaces In the case where it is formed by a connection region or the like that smoothly connects the portion 16, the boundary between the optical portion 14 and the peripheral portion 16 on the front and rear surfaces of the lens does not necessarily have to be clearly defined as a line in terms of shape. It is grasped by the outer peripheral edge of the optical unit set so as to exert a desired optical action on the optical system of the eye.

In addition, the purpose of sufficiently ensuring the stability of the appearance when worn is to set the diameter dimension D _oz of the optical unit 14 to 0.5 or more and 0.55 or more with respect to the lens outer diameter dimension (DIA). However, in consideration of conditions such as tear fluid of the wearing eye and corneal surface shape, it is preferable to set the D _oz / DIA value to 0.6 or more as described above. . However, setting the value of D _oz / DIA to 0.65 or more or 0.7 or more may be more preferable in order to obtain the effect of improving the appearance stability.

Further, in the optical unit 14, the rear optical unit 18 serving as a rear surface positioned on the cornea side in the wearing state has a lens central axis so as to be substantially similar to the surface of the attached cornea in the wearing state. 12, the center of curvature is set behind the lens (to the right in FIG. 2), and a base curve (BC) having a concave longitudinal sectional shape with an appropriate curvature radius: X is attached. In consideration of the shape of the cornea, other wearing conditions, or required optical characteristics, for example, the radius of curvature is constant or the radius of curvature changes in the circumferential direction in the longitudinal cross-sectional shape of the rear optical unit 18. Various substantially spherical curved concave shapes such as are adopted. The radius of curvature of the base curve (BC) attached to the rear optical unit 18: X is 7.00 mm to 9.00 mm, more preferably 7.40 mm to 8.80 mm, and still more preferably 7.90 mm to 8.80 mm. It is set within a range of 50 mm.

In particular, the contact lens 10 of the present embodiment sets the upper limit of the fitting range of the curvature radius Y of the cornea C of the wearer beyond the curvature radius X of the base curve (BC) attached to the rear optical unit 18. It is possible. Here, the compatible range of the radius of curvature of the cornea Y is a range of the radius of curvature of the cornea that does not adversely affect the appearance and feeling when the contact lens is worn, for example, the amount of movement of the contact lens with respect to the cornea when blinking Δ means 0 <Δ <1 mm. In addition, when the cornea has an elliptical shape or the like, and the corneal curvature radius Y is anisotropic, the corneal curvature radius Y can adopt an average value.

When the radius of curvature of the cornea: Y is larger than the radius of curvature of the base curve (BC): X, there is a possibility that the attractive force of the contact lens 10 on the corneal surface may be increased, but according to the contact lens 10 of the present embodiment, Since the lens outer diameter (DIA) is set small, the amount of movement on the corneal surface can be secured, and the radius of curvature of the base curve (BC): also applicable to corneas with a radius of curvature exceeding X can do.

In addition, the contact lens 10 may set the lower limit of the fitting range of the wearer's corneal curvature radius: Y to a side smaller than the curvature radius: X of the base curve (BC) attached to the rear optical unit 18. In addition, the conforming range between the upper limit and the lower limit of the conforming range of the corneal curvature radius: Y can be set in a range exceeding 0.65 mm.

For example, as shown in Examples 3 to 5 to be described later, when the curvature radius of the base curve (BC): X is 8.30 mm, the upper limit of the applicable range of the corneal curvature radius: Y is from 8.30 mm. Can also be set to a large 8.32 mm. On the other hand, the lower limit of the compatible range of the corneal curvature radius: Y can be set to 7.48 mm, which is smaller than 8.30 mm. Thereby, the adaptation range between the upper limit and the lower limit of the adaptation range of the corneal curvature radius Y can be set to 0.84 mm between 7.48 mm and 8.32 mm. As also shown in Example 2 described later, when the curvature radius of the base curve (BC): X is 8.10 mm, the upper limit of the compatible range of the corneal curvature radius: Y is 8.32 mm, and the lower limit is 7 It can be set to .48 mm, and the fitting range between the upper limit and the lower limit of the fitting range of the corneal curvature radius: Y can be set to 0.84 mm from 7.48 mm to 8.32 mm.

Such a contact lens 10 has a short-term use period within 3 months, for example, 3 months, 1 month, 2 weeks, 1 week, or 1 day, and is discarded after the expiration date. It is a type.

The contact lens 10 can be manufactured by a cutting and polishing method or a spin cast method that has been conventionally used for manufacturing a contact lens. However, preferably, the contact lens 10 is conventionally manufactured by a disposable soft contact lens. It is manufactured by a mold polymerization method that is widely used. The mold polymerization method is a manufacturing method in which a target contact lens is manufactured by filling and polymerizing a polymerizable monomer mixed solution in a mold having a molding cavity corresponding to a target lens shape, and there are few types of lenses. Therefore, it is possible to mass-produce soft contact lenses that require fewer types of molds to be prepared at low cost.

Like the conventional contact lens, such a contact lens 10 keeps the upper and lower eyelids of the eye to be worn open with one hand while the contact lens 10 placed on the finger of the other hand is in the eye. Place the contact lens 10 on the corneal surface by approaching it, place the contact lens 10 on the finger of one hand, pull down the lower eyelid with the other finger, and pull up the upper eyelid with the finger of the other hand. It is worn by attaching it to the corneal surface. And according to the contact lens 10 of this embodiment, the lens outer diameter dimension (DIA) is made small compared with the disposable soft contact lens generally used. This makes it possible to reduce the fear given to the user when wearing the eye. For example, even a person who uses contact lenses for the first time, a beginner who has just started using it, or a child who is likely to have fear. The lens can be worn smoothly.

The contact lens 10 is a disposable type in which a short-term use period within 3 months is set. Therefore, even a user who is unfamiliar with the handling of the contact lens or has a poor handling can replace the lens with a new lens before the contact lens 10 accumulates dirt such as lipids and proteins to the eye. Hygiene can be ensured.

Further, since the lens outer diameter dimension (DIA) is small and the adsorption action to the corneal surface is small, for example, even when the curvature radius of the corneal surface: Y is larger than the curvature radius of the base curve (BC): X, on the cornea The amount of movement can be secured. On the other hand, when the radius of curvature of the corneal surface: Y is smaller than the radius of curvature of the base curve (BC): X, the lens outer diameter dimension (DIA) is set small, thereby reducing friction with the eyelid. It is possible to suppress movement more than necessary, and even if it moves, the optical unit 14 is set to a lens outer diameter of 0.6 or more and formed at a large ratio with respect to the lens outer diameter dimension (DIA). Therefore, a good appearance can be maintained. Thereby, it becomes possible to cope with the curvature radius Y of the corneal surface in a wider range. For example, the types of lenses can be reduced, and the manufacturing cost can be reduced.

In order to confirm the technical effect of the contact lens according to the present invention, for the contact lens as a comparative example according to the conventional structure and the contact lens as an example according to the present invention, [I] optical portion relative to the lens outer diameter (DIA) The results of investigation on the setting range of the diameter dimension (D _oz ) and the application range of the corneal curvature radius (Y) with respect to the curvature radius (X) of [II] lens base curve are shown below.

[I] Setting range of optical part diameter dimension (D _oz ) with respect to lens outer diameter dimension (DIA) As examples, three types of soft contact lenses of Example A, Example B and Comparative Example A shown in [Table 1] Prepared. In [Table 1], the Menicon Soft 72 material used as the lens material is a material under the trade name “Menikon Soft 72” of Menicon Co., Ltd., which is DMAA (dimethylacrylamide) and N-VP (N-vinylpyrrolidone). Non-ion having a oxygen transmission coefficient (Dk value) of 34 (according to ISO electrode method, unit: × 10 ^-11 (cm ² / sec) · (mLO ₂ / (mL · mmHg))) It is a highly water-containing material. Using this material, a total of three types of soft contact lenses of Examples A and B and Comparative Example A were prototyped by a known race cut method using a lathe. Each contact lens is worn in a swollen state, and the lens outer diameter dimension (DIA), optical part diameter dimension (D _oz ), lens base curve curvature radius (X), etc. are all physiological. The measured value in a swollen state with saline solution.

Then, these three types of soft contact lenses are worn by subjects who meet P (additional power), BC (X), and DIA, and the appearance after 15 minutes from wearing is defined as “stability”. Two items of "clearness" were evaluated by subject's subjective observation. The former “stability” evaluation employed an evaluation method in which the appearance was selected from four items of “stable”, “almost stable”, “slightly unstable”, and “unstable”. The latter “clearness” evaluation was evaluated as being defective when it took less than 2 seconds from right after blinking until it was clearly visible, and when it took 2 seconds or more to be clearly visible. The evaluation results of “stability” and “sharpness” are shown in [Table 2] below.

Such as apparent from Table 2 the results, also the lens outer diameter (DIA) is a small-diameter contact lens 13.20Mm, diameter of the optical portion (D _oz) is large, for example, D _oz It can be seen that in the contact lens in which the ratio of / DIA is set to 0.6 or more, both the stability of the appearance in the wearing state and the sharpness can be kept good. That is, in the contact lenses of Examples A and B and Comparative Example A, not only the lens material and P (additional lens power) but also BC and DIA are the same, but the ratio of D _oz / DIA is 0. The contact lens of Comparative Example A having a ratio of less than 6 is difficult to obtain both stability and sharpness, whereas the contact lenses of Examples A and B having a D _oz / DIA ratio of 0.6 or more are difficult to obtain. , Good appearance is demonstrated. Further, regarding the stability of the contact lens on the cornea, the ratio of D _oz / DIA is set to 0.6 or more according to the present invention, and the ratio of the peripheral portion is limited. As a result, the influence on the stability and sharpness during wearing is reduced, and as a result, good stability and clearness can be exhibited within a wide range of DIA of 10 mm to 13.5 mm.

[II] Range of application of corneal curvature radius (Y) to curvature radius (X) of lens base curve As examples, seven types of soft contact lenses of Examples 1 to 6 and Comparative Example 1 shown in [Table 3] are prepared. did. Each of these seven types of soft contact lenses is made of silicone hydrogel, which is a material under the trade name “2 Week Menicon Premio” of Menicon Co., Ltd., and is based on an oxygen transmission coefficient (Dk value) 129 (ISO electrode method). Unit: × 10 ^-11 (cm ² / sec) · (mLO ₂ / (mL · mmHg))). Using these materials, a total of seven types of soft contact lenses of Examples 1 to 6 and Comparative Example 1 were prototyped by a known molding method using a resin molding die. Incidentally, in Comparative Example 1, a commercially available disposable soft contact lens (trade name: 2-week Menicon Premio manufactured by Menicon Co., Ltd.), which is a conventional product, was used.

In this example in which the range of application to the cornea is measured based on the amount of motion, the condition is made as common as possible with the additional lens power (P) being −3 diopters in any soft contact lens. In the contact lens of Comparative Example 1, the D _oz / DIA ratio was small and less than 0.6 when the DIA value was 14.00 mm.

The BC (X value) is different in the range of 7.40 to 8.40 mm, and the DIA is different in the range of 12.50 to 13.50 mm, which is a total of 7 types including the comparative example of the conventional standard. These soft contact lenses were worn by a plurality of subjects having different corneal curvature radii, and the amount of movement on the cornea was objectively measured and evaluated after 15 minutes from wearing. In this evaluation, the distance that the contact lens moved on the cornea at the time of blinking was measured as the amount of movement, and “normal” was determined when the measured value of the amount of movement was greater than 0 and less than 1 mm. On the other hand, the case where the measured value of the motion amount was 0 mm and the tight was not moving, and the case where the measured value of the motion amount was 1 mm or more and the body was too loose was determined to be “non-conforming”. The results of measurement and evaluation are shown in [Table 4] below. In addition, in order to make it easy to understand the suitability of a contact lens having a specific BC to a cornea having a wide radius of curvature range, it is impossible when the conforming range of the matching corneal curvature radius is 0.65 mm or less (× The results of determination based on the amount of motion are also shown in [Table 4].

In addition, as subjects, a plurality of persons including those having a curvature radius of the cornea of 7.48 mm, 7.69 mm, 8.07 mm, 8.32 mm, and 8.41 mm were employed. As shown in [Table 4], in Examples 1 to 6, it was confirmed that the amount of motion was within a range of greater than 0 and less than 1 mm within a wide upper and lower limit range of a corneal curvature radius of at least 0.84 mm. Although it was good and obtained, Comparative Example 1 could only confirm a narrower range of 0.38 mm, and if it was outside this range, the amount of movement was 0 (no movement) or 1 mm or more, which was not suitable. there were.

By the way, the upper and lower limits of the corneal curvature radius adapted in Comparative Example 1 (the amount of motion was in the range of greater than 0 mm and less than 1 mm) were 8.07 mm and 7.69 mm, and the upper limit was higher than the BC of the contact lens It was small and the fitting range was narrow. Moreover, in the contact lenses of any of the examples, the amount of movement during blinking was suppressed to less than 1 mm in the wearing state on the cornea having a curvature radius of 7.48 mm, and the compatibility was good. In the contact lens of Comparative Example 1, the amount of motion exceeded 1 mm even with a cornea having a radius of curvature of 7.48 mm, which was incompatible. Incidentally, the amount of movement measured with the 7.48 mm cornea attached was 0.2 mm in Example 1, 0.4 mm in Example 2, 0.4 mm in Example 3, and 0.1 mm in Example 4. In Example 5, it was 0.3 mm, and in Example 6, it was 0.3 mm. On the other hand, on the upper limit side of the applicable corneal curvature radius, the movement amount at the time of blinking in the wearing state on the cornea having the curvature radius of 8.32 mm is 0.3 mm in Example 1, and 0.5 mm in Example 2. Example 3 is 0.5 mm, Example 4 is 0.5 mm, Example 5 is 0.3 mm, and in Example 6, the amount of movement at the time of blinking is reduced even when worn on a cornea having a radius of curvature of 8.41 mm. While 0.3 mm could be ensured, in Comparative Example 1, the amount of movement at the time of blinking was 0 (none) even when worn on a cornea having a radius of curvature of 8.07 mm.

In addition, for measurement of the radius of curvature of the subject's cornea, a commercially available autokeratometer (manufactured by Topcon Co., Ltd., model name: KR-8100P) was used, and the radius of curvature of the cornea in the region of about 3 mm from the center of the cornea was vertical. The average value in these two directions was used as the value of the corneal curvature radius (R). Furthermore, the base curve of the contact lens is the radius of curvature of the rear optical part of the surface having a single refractive element, and the soft contact lenses of the example and the comparative example are made to be a rotation target shape. Measured by projecting an image from the side of a soft contact lens immersed in physiological saline onto a screen using JCF / TCU (model name) manufactured by (Optimec Limited) and reading the base curve radius (BCOR) did.

As is apparent from [Table 4], each of the soft contact lenses of Examples 1 to 6 has a wider range of twice or more than the comparative example 1 which is a conventional general DIA soft contact lens. It was confirmed that it can be adapted to the corneal curvature radius. In particular, for both the upper limit and the lower limit of the adaptation range, each of Examples 1 to 6 can be applied to a wider range than the comparative example, and the comparative example has a larger radius of curvature than the base curve (BC). However, according to each example, it was confirmed that the present invention can also be applied to a corneal shape having a radius of curvature exceeding the base curve (BC).

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 contact lens illustrated in the above embodiment is a single-focus contact lens, but also for bifocal for presbyopia correction, progressive multifocal (progressive) contact lens, toric contact lens for astigmatism correction, etc. The present invention can be suitably applied.

In particular, in the toric contact lens for correcting astigmatism, it is also possible to set the cylindrical lens power on the base curve side, in which case the anisotropy occurs in the radius of curvature of the base curve, but with regard to the range of adaptation to the cornea Can be dealt with by adopting an average value as in the cornea.

Further, as the shape of the outer periphery of the contact lens, the optical part, etc., it is possible to adopt a shape other than a circle such as an ellipse, for example. In that case, as in the case of setting the cylindrical lens power, Known circumferential positioning means such as prism ballast can be employed.

10: contact lens, 12: lens central axis, 14: optical part, 16: peripheral part, 17: edge part, 18: rear optical part

Claims

A peripheral part is provided in the outer peripheral area of the optical part in the central area, and is a contact lens that is worn by being superimposed on the eye,
It is a soft type made of a flexible material and a disposable type with a short-term expiration date set within 3 months.
A contact lens, wherein the lens outer diameter is set within a range of 10 to 13.5 mm, and the diameter of the optical portion with respect to the lens outer diameter is set to 0.6 or more.
The contact lens according to claim 1, wherein an upper limit of a conforming range of the wearer's corneal curvature radius Y can be set beyond a curvature radius X of a base curve attached to a rear surface of the optical unit.
The lower limit and upper limit of the fitting range of the wearer's corneal curvature radius Y are set to be smaller and larger than the curvature radius X of the base curve attached to the rear surface of the optical unit, and the upper limit and lower limit The contact lens according to claim 1, wherein the fitting range can be set in a range exceeding 0.65 mm.
4. The amount of movement associated with blinking when wearing a cornea having a radius of curvature of at least X + 0.01 mm is greater than 0 mm, where X is the radius of curvature of the base curve attached to the rear surface of the optical unit. The contact lens according to one item.
The contact lens according to any one of claims 1 to 4, wherein a range of corneal curvature that is larger than 0 mm and less than 1 mm is present in a range of corneal curvature exceeding 0.65 mm under wearing conditions.