JPH0728002A - Ophthalmic lens - Google Patents

Abstract

PURPOSE:To provide an ophthalmic lens which is decreased in chromatic aberrations and satisfies fashionability and wearing feel due to its small thickness and light weightness by combining >=2 kinds of lenses varying in Abbe number and ruggedness. CONSTITUTION:Two kinds of the lenses L1, L2 varying in the Abbe number and concavity/convexity are combined. The lens L2 is used to provide diopter and a blank material having a higher refractive index is more preferably in terms of the small thickness and light weightness as its blank material. A blank material having a large Abbe number is used. The lens L1 has a role of correcting the chromatic aberrations and a blank material preferably having a small Abbe number is used. The smaller refractive index is more preferably in order not to impair the diopter possessed by the lens L2. A difference in the Abbe number between the lenses L1 and L2 is preferably >=5. The blank materials to be used for the lenses L1, L2 are preferably resins having a crosslinked structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectacle lens, and more particularly to a spectacle lens which has a small chromatic aberration and allows an object to be viewed without any discomfort.

[0002]

2. Description of the Related Art Conventionally, glasses have often been used for glasses in glasses, but in recent years, plastic materials have been often used.

In particular, a thin plastic lens using a resin having a high refractive index of 1.60 or more is widely used.

It is considered that the share of high refractive index lenses will continue to increase in the future. However, in plastics, when the refractive index is high, the chromatic aberration is large (the Abbe number is small) in many cases.

Chromatic aberration is caused by a difference in refractive index depending on the wavelength of light.

When the chromatic aberration becomes large, when an object is viewed, color bleeding is seen in the peripheral part of the object, which often causes a sense of discomfort, especially in a lens having a high power (the absolute value of the diopter value of the lens is large). , Noticeable when looking at things.

Up to now, a person who feels such a chromatic aberration can only use a lens having a small chromatic aberration, that is, a low refractive index.

[0008]

However, most people who are worried about chromatic aberration use spectacle lenses with high power, and when these people use lenses with low refractive index,
Since the thickness of the peripheral portion becomes large and the lens becomes heavy, there arises a problem that fashionability and wearing feeling are deteriorated.

An object of the present invention is to provide a spectacle lens in which chromatic aberration of the spectacle lens can be reduced so that an object can be seen without any discomfort, and at the same time, the thinness and lightness of the spectacle lens can satisfy fashionability and wearability. And

[0010]

[Means for Solving the Problems] As means for achieving this, the following constitution is provided.

"A spectacle lens characterized by combining two or more kinds of lenses having different Abbe numbers and different unevenness." The Abbe number is one index representing chromatic aberration, and a material having a large value is A material having a small chromatic aberration and conversely a small value has a large chromatic aberration.

Although the Abbe number of the material used is not particularly limited, it is preferable to use a material having a difference in Abbe number of 5 or more as a material having different irregularities.

For two or more types of lenses, it is most preferable to use two types of lenses in view of ease of manufacturing and lens design.

The role of these two types of lenses is that one lens (lens 1) produces a power, and the other lens (lens 2) has a role of correcting chromatic aberration.

The sign (+ or-) of the lens power (diopter) produced by combining the two lenses coincides with the sign of the power of the lens 1.

Since the material used for the lens 1 is related to the power of the finished lens, it is preferable to use a material having a higher refractive index in terms of thinness and lightness.
It is preferable to use a material having a large Abbe number.

The material used for the lens 2 is the lens 1
It is preferable to use a material having a small Abbe number in order to correct the chromatic aberration that occurs in (1), and it is preferable that the refractive index is small in order not to impair the power of the lens 1 as much as possible.

As a material used for these lenses, plastic is preferable from the viewpoint of light weight.

Further, when the finished lens is used as a spectacle lens, since it is heated in the steps such as surface processing and polishing, heat resistance is required. Therefore, a resin having a crosslinked structure is preferable.

Various methods can be used as a method of combining lenses having different projections and depressions according to the present invention.

One method is a method in which lenses manufactured separately are attached to each other with an adhesive.

It is also possible to manufacture by manufacturing the one lens and then using the lens as a part of the mold to mold the other lens.

Since the lens obtained in the present invention is used as a spectacle lens, it is necessary that the two kinds of lenses are in close contact with each other without having a space.

A cross-sectional view of the lens obtained in the present invention, which passes through the center of the lens, is shown in FIGS.

The material used for the lens is not particularly limited, but a resin containing a sulfur atom or a bromine atom is preferable as the material of the lens 1 described above, and specifically, a compound represented by the following general formula 1 is used. What was obtained by polymerizing the monomer composition containing is preferable.

[0026]

[Chemical 1] In the formula, R ¹ represents hydrogen or a methyl group, and k represents an integer of 1 to 3. l is an integer of 0 to 3, m is an integer of 0 to 2, and n is 0.
Indicates an integer of 2. i is an integer of 1 to 5, h is an integer of 0 or 1.

Further, as the material of the lens 2, it is preferable to use a resin containing a benzene ring or a naphthalene ring.
Specifically, those obtained by polymerizing a monomer composition containing a compound represented by the following general formula 2 are preferable.

[0028]

[Chemical 2] In the formula, p is an integer of 0 to 3, q is an integer of 0 to 2, and r is 0.
2 is an integer, t is an integer of 1 to 3, u is an integer of 0 or 1.

The compound represented by the general formula 1 or 2 can be copolymerized with a known monomer.

For example, an olefin compound having a radically polymerizable functional group can be mentioned, but it is not particularly limited.

Specific examples include (meth) acrylic compounds, styrene compounds, acrylonitrile, N-phenylmaleimide and the like. Specifically, methyl (meth)
Acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Examples thereof include cyclohexylmethylene (meth) acrylate, styrene, vinylnaphthalene, halogen-substituted styrene, and α-methylstyrene.

By copolymerizing a monomer having two or more radically polymerizable functional groups in the molecule, a resin having a crosslinked structure having excellent heat resistance can be obtained. The monomer having two or more radically polymerizable functional groups in the molecule is not particularly limited, but examples thereof include two or more radically polymerizable functional groups in the molecule such as divinylbenzene and diallyl phthalate. By using the compound having the above, a lens having excellent heat resistance can be obtained. The monomer having two or more radically polymerizable functional groups in the molecule is not particularly limited, but examples thereof include divinylbenzene, diallyl phthalate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth). Acrylate, triethylene glycol di (meth) acrylate, bisphenol A-di (meth) acrylate,
Bisphenol A-di (hydroxyethyl (meth) acrylate, tetrabromobisphenol A-di (meth) acrylate
Acrylate, tetrabromobisphenol A-di (hydroxyethyl (meth) acrylate), triallyl isocyanurate, pentaerythritol tetrakis (meth) acrylate, pentaerythritol tris (meth) acrylate, diethylene glycol bisallyl carbonate and the like.

Further, in the case of a resin having a crosslinked structure, since it is excellent in heat resistance, peeling due to thermal deformation at the interface of the combination hardly occurs, and when the combined lens is manufactured by the sequential manufacturing method, The lens manufactured in 1) has the advantage that it can be prevented from undergoing thermal deformation during manufacturing of the lens manufactured later.

In the above polymerization, an ultraviolet absorber, an antioxidant and the like can be used, if necessary, in order to improve the quality of the lens.

The surface shape of the lens manufactured in the present invention may be not only a spherical surface but also an aspherical surface or a free surface such as progressive multifocal point.

Further, by providing a hard coat film or an antireflection film on the surface of the resin obtained in the present invention, an optical article having excellent surface characteristics can be manufactured.

[0037]

EXAMPLES The present invention will be specifically described with reference to the following examples.

The chromatic aberration of the lens was evaluated by measuring the diopter of the lens using lights having different wavelengths (480 nm, 578 nm, 656 nm).

It is considered that the smaller the difference in the frequency depending on the wavelength, the smaller the chromatic aberration.

Example 1 A glass composition was prepared by using a monomer composition consisting of 9.5 parts by weight of styrene and 0.5 parts by weight of benzoyl peroxide in 90 parts by weight of a monomer having a structure represented by the following formula A. Casting polymerization with a mold consisting of a gasket made of vinyl chloride and vinyl chloride, front curve R = 584 mm, back curve R = 50 mm, center thickness = 0.3 mm, lens diameter φ =
A 70 mm lens 1 was molded.

In a similar manner, 50 parts by weight of the monomer having the structure represented by the following formula B was polymerized with a monomer composition comprising 49.5 parts by weight of styrene and 0.5 part by weight of benzoyl peroxide. Then, the front curve R = 300m
m, back curve R = 584 mm, center thickness = 1.0 m
A lens 2 having a diameter of m and a lens diameter of φ = 70 mm was molded.

The front curve of the lens 1 and the back curve of the lens 2 were adhered to each other with a commercially available adhesive (Balsum, Canada).

Table 1 shows the dioptric power for each wavelength of this lens.

[0044]

[Chemical 3] Comparative Example 1 50 parts by weight of a monomer having a structure represented by the following formula C, 49.5 parts by weight of styrene, and 0.5 parts of benzoyl peroxide.
A monomer composition consisting of parts by weight was polymerized to form a lens having a front curve R = 300 mm, a back curve R = 50 mm, a center thickness = 1.3 mm, and a lens diameter φ = 70 mm.

It was possible to obtain a lens whose external shape was almost the same as that of the lens obtained in Example 1. Table 1 shows the dioptric power of each wavelength of this lens.

[0046]

[Chemical 4]

[Table 1]

[0047]

INDUSTRIAL APPLICABILITY The present invention relates to a novel spectacle lens, and it is possible to manufacture a spectacle lens which has small chromatic aberration, is thin and lightweight, and is excellent in fashionability.

[Brief description of drawings]

FIG. 1 shows a cross-sectional view of a spectacle lens of the present invention (in the case of a minus lens).

FIG. 2 shows a sectional view of the spectacle lens of the present invention (in the case of a plus lens).

[Explanation of symbols]

L1: a plus lens using a low Abbe number base material L2: a minus lens using a material with a higher Abbe number than L1 L3: a plus lens using a material with a higher Abbe number than L4 L4: using a low Abbe number material Minus lens

Claims (4)

[Claims] 1. Two different Abbe numbers and different unevenness
An eyeglass lens characterized by combining more than one type of lens. 2. The spectacle lens according to claim 1, wherein the lenses having different irregularities are made of a resin having a crosslinked structure. 3. The lens according to claim 1, wherein the base material of one of the lenses having different irregularities is made of a resin obtained by polymerizing a monomer containing a sulfur atom or a naphthalene ring. Spectacle lens. 4. The spectacle lens according to claim 1, wherein the Abbe numbers differ by 5 or more.