JP5632776B2 - Medical glasses for patients with double vision or low vision - Google Patents

Description

  The present invention relates to medical eyeglasses for patients with diplopia or amblyopia used to treat diplopia or amblyopia.

  Conventionally, medical glasses as listed in Patent Document 1 have been proposed to correct the visual acuity of patients with amblyopia or double vision. The medical eyeglasses of Patent Document 1 are lenses that are fogged with a rough surface with fine irregularities so that the eye on the side causing double vision in double vision and the normal eye in low vision are scattered and light is blurred. And the other lens is a normal transparent lens. By using such medical spectacles, it can be expected that the double vision is lost or the visual acuity is restored.

JP-A-8-82773

In the medical spectacles as described above, when one of the lenses is fogged, conventionally, the entire haze is basically set to be uniform. For this reason, as shown in FIG. 6, the appearance of the image (luminous transmittance) when transmitted from a directly opposed position throughout the lens is substantially uniform throughout the lens. However, when the luminous transmittance based on the pupil position is considered, the lenses set in this way do not necessarily have the same luminous transmittance in all line-of-sight directions. As shown in FIG. 7, the luminous transmittance tends to be lower when the lens is viewed obliquely in the direction facing the lens with respect to the pupil position and the direction in which the lens is viewed obliquely.
This is because light in an oblique direction is incident at an angle with respect to the concavo-convex surface, so that there is light that is more easily scattered than the light in the front direction and does not reach the pupil. The amount of scattering increases in the oblique direction due to the long distance (top-to-top distance), or attenuates within the lens because the distance through which light passes through the lens is longer in the oblique direction. This is because the amount increases.
For this reason, in the past, the visual luminous transmittance when looking obliquely and when looking forward is different, so when using such medical glasses, it becomes visible as the line of sight moves. I felt uncomfortable and put a strain on my eyes, making it easy to get tired.
The present invention has been made paying attention to such problems existing in the prior art. The purpose is medical glasses for patients with double vision or low vision who can reduce discomfort and fatigue caused by visual observation through the lens on the clouded side when one eye is covered with the clouded lens. Is to provide.

In the invention of claim 1 for solving the above-described problem, the fogging process is performed on one of the left and right pair of lenses, and the fogging rate of the central portion of the one lens is set to the surrounding portion. The gist of this is to make the luminous transmittance uniform between the portion near the center of the one lens and the surrounding portion with respect to the pupil position.
Further, the gist of the invention of claim 2 is that, in addition to the configuration of the invention of claim 1, the change in the fogging rate continuously changes in the boundary region between the central portion of the lens and the surrounding portion. .
The gist of the invention of claim 3 is that, in addition to the configuration of the invention of claim 1 or 2, the clouding rate decreases as the peripheral portion of the lens is separated from the central portion of the lens.
In the invention of claim 4, in addition to the structure of any one of claims 1 to 4, the fogging treatment for the one lens is a roughening treatment on at least one of the front and back surfaces of the lens. Is the gist.
Further, in the invention of claim 5, in addition to the structure of the invention of claim 4, the gist is that a coat layer is formed on at least one of the front and back surfaces of the one lens subjected to the rough surface treatment. To do.
In addition to the configuration of any one of the first to fifth aspects, the gist of the invention of claim 6 is that the pair of left and right lenses are colored.
Further, in the seventh aspect of the invention, in addition to the configuration of any one of the first to sixth aspects, a mirror coat layer is formed on the surface of the pair of left and right lenses facing the object side. To do.

In the case of medical glasses for patients with double vision or amblyopia having the above-described configuration, a lens near one of the left and right lenses that has been fogged for double vision or amblyopia is located around the center portion of the lens. Since the fogging rate is higher than that of the area, there is no significant difference in the actual luminous transmittance between the front view and the oblique view when the pupil position is used as a reference, and the view between the central portion of the lens and its peripheral portion is eliminated. Homogenization of the transmission sensitivity will be achieved.
For the fogging of the lens, at least one of the front and back surfaces of the lens may be blasted to form a fine uneven surface, and a mold is used to form a fine uneven surface on at least one of the front and back surfaces of the lens. Any means may be used even if fine particles that scatter light are dispersed in the resin.
The central portion of the lens is a certain area around the center position of the pupil when facing the front (generally about 5 to 10 mm vertically and about 10 to 30 mm horizontally), and the surrounding area is clear. There is no reason. For this reason, it is desirable that the change in the clouding rate in the boundary region between the central portion of the lens and the surrounding portion does not change discontinuously, but gradually changes. Further, the peripheral portion of the lens may be designed to have a uniform haze rate, or may be designed so that the haze rate decreases as the distance from the central portion of the lens increases.
In addition, when the surface of the lens is roughened by blasting or using a mold, it is preferable to form a coat layer on the roughened surface.

The pair of left and right lenses are preferably colored. This makes it difficult to recognize the unnaturalness that the lens is clouded when viewed from others, and the external light entering the eyes is limited, reducing the burden on the eyes.
Further, a mirror coat layer is preferably formed on the surface of the pair of left and right lenses facing the object side. This makes it difficult to recognize the unnaturalness that the lens is clouded when viewed from others.

  In the invention of each of the above claims, when a patient with double vision or amblyopia uses a lens in which one of the left and right lenses is clouded for the treatment, the clouded lens is viewed from the front and oblique directions. Homogeneity of the luminous transmittance at the time of viewing will be achieved, and the uncomfortable feeling and fatigue when using such medical glasses will be reduced.

The front view of the medical spectacles of embodiment of this invention. Explanatory drawing explaining the structure of the lens in the cross section in the AA of FIG. The graph explaining the distance from the optical center in a 1st lens, and the characteristic of arithmetic mean rough surface roughness (Ra). The graph which compares and shows the relationship between the distance from the optical center of a 1st lens and the conventional lens, and luminous transmittance. The graph explaining the distance from the optical center in the 1st lens in other embodiment, and the characteristic of arithmetic mean roughness (Ra). Explanatory drawing explaining the method of the measurement of the luminous transmittance with respect to the lens clouded uniformly. Explanatory drawing explaining the pupil position at the time of actually visually observing the lens clouded uniformly, and its gaze direction.

Hereinafter, this embodiment of the medical glasses of the present invention will be described with reference to the drawings.
As shown in FIG. 1, in the medical spectacles 11, two first and second lenses 13 and 14 are attached to a lens frame 12. The lens of the present embodiment has an inverted trapezoidal shape with a maximum width of 50 mm and a width of 30 mm. Temples 15 are foldably attached to both sides of the lens frame 12. As shown in FIG. 2, a hard coat layer 16 and a mirror coat layer 17 are formed on the surfaces of both lenses 13 and 14 in this order from the lens side. A hard coat layer 16 and a multi-coat (antireflection film) layer 18 are formed on the back surfaces of the lenses 13 and 14 in this order from the lens side. In the present embodiment, the reflectance of the mirror coat layer 17 is set to 20%. Both lenses 13 and 14 are plastic lenses colored in brown, and in this embodiment, the absorptance is set to 65%.
Fine irregularities are formed on the back surface of the first lens 13 by blasting. The hard coat layer 16 is formed on this fine unevenness. As shown in FIG. 1, the first lens 13 has a region of a circle having a radius of 5 mm centered on the optical center O as a region A, and a periphery thereof as a region B. The area A is set to have a higher haze ratio than the area B. Here, the fogging rate, that is, how much cloudiness is caused, was obtained by using the arithmetic average roughness (Ra) obtained in the blasting process as a parameter. When the numerical value of arithmetic average rough surface roughness (Ra) increases, the degree of cloudiness increases, and this indicates the level of fogging.
As shown in FIG. 3, in this embodiment, the arithmetic average roughness (Ra) of the region A near the center of the first lens 13 is set to 0.6 μm. On the other hand, for the region B, the arithmetic average roughness (Ra) is gradually set to be small so that the change is continuous with the boundary region extending from the boundary with the region A to a distance of 2 mm (5 to 7 mm from the center). The arithmetic average roughness (Ra) of the outer region was set to 0.5 μm. In FIG. 1, the boundary between the region A and the region B is clearly shown, but the boundary between the region A and the region B is actually unclear depending on the boundary region.
FIG. 4 shows a case where the line of sight is moved from the vicinity of the center of the first lens 13 of the medical spectacles 11 to the lens of the medical spectacles having the conventional uniform arithmetic average roughness (Ra). It is a graph which compares and shows the change of luminous transmittance. In the conventional lens, the luminous transmittance is lowered at the periphery, but in the present embodiment, the luminous transmittance of the periphery is changed so as not to be lowered as compared with the vicinity of the center.

Such medical spectacles 11 have the following effects.
(1) When using as a medical spectacle 11 for a diplopia or amblyopic patient, the lens (first lens 13) on the side subjected to the fogging treatment as described above is a region A having a high fogging rate and its surroundings. Since the area B has a relatively low fogging rate, the difference between the vicinity of the center and the periphery is not large in the luminous transmittance when actually used, and the appearance of both can be homogenized. As a result, it is possible to reduce the discomfort and fatigue of the user. In addition, since the clouding rate gradually changes from the region A through the boundary region, the user does not feel a sudden change in brightness when moving his / her line of sight, so use it with a natural feeling. Can do.
(2) Since both lenses 13 and 14 are colored brown, the amount of external light entering the eyes is reduced, and it is difficult for a third party to recognize that one lens 13 is cloudy medical glasses 11. ing.
(3) Since the mirror coat layer 17 is formed on the surfaces of both lenses 13 and 14, in addition to the effect of (2), it is difficult for a third party to recognize that one lens 13 is cloudy.
(4) Since the multi-coat layer 18 is formed on the back surfaces of the both lenses 13 and 14, so-called reflection of the scenery in which the rear scenery generated when the mirror coat layer 17 is provided is reflected on the mirror coat layer 17 is prevented. It is possible to improve the visibility when the mirror coat layer 17 is provided.

It should be noted that the present invention can be modified and embodied as follows.
-The setting of the arithmetic mean roughness (Ra) of the area | region A and the area | region B is not limited above. For example, as shown in FIG. 5, it is possible to set so that the arithmetic average roughness (Ra) becomes smaller in the region B toward the outside.
-It is also possible to use 10-point average roughness (Rz) other than arithmetic average roughness (Ra) as a parameter of the fogging rate, or a haze value by a haze meter.
The setting of the lens material, lens shape, arithmetic mean roughness (Ra), lens color and density (absorption rate), mirror reflectivity, etc. is an example, and can be changed as appropriate.
The first lens 13 using the colored plastic lens as described above may be set to a substantially uniform arithmetic average roughness (Ra) without being divided into the regions A and B. That is, more preferably, as the medical spectacles 11 of a colored lens that changes the clouding rate by dividing into the region A and the region B as in the above embodiment, but does not change the clouding rate. It can also be realized.
It is also possible to realize that the mirror coat layer 17 is not formed when a colored plastic lens is used.
-When coloring the lens, it is free to use a color other than brown or other absorption rate.
In addition, it is free to implement in a mode that does not depart from the spirit of the present invention.

  11 ... medical spectacles, 13 ... first lens as one lens.

Claims (7)

  The one of the pair of left and right lenses is subjected to the fogging process, and the one with the pupil position as a reference is set by making the fogging rate of the central portion of the one lens higher than the surrounding portion. Medical glasses for patients with double vision or amblyopia, characterized in that homogeneity of luminous transmission between the central portion of the lens and its peripheral portion is made uniform.   The medical spectacles for patients with double vision or amblyopia according to claim 1, wherein a change in the clouding rate is continuous in a boundary region between a central portion of the lens and a peripheral portion thereof.   The medical spectacles for patients with double vision or amblyopia according to claim 1 or 2, wherein the clouding rate decreases as the peripheral portion of the lens is separated from the central portion of the lens.   The fogging process for the one lens is a rough surface process on at least one of the front and back surfaces of the lens. Medical glasses.   The medical glasses for patients with double vision or amblyopia according to claim 4, wherein a coat layer is formed on at least one of the front and back surfaces of the one lens subjected to the rough surface treatment.   The medical glasses for patients with double vision or low vision according to any one of claims 1 to 5, wherein the pair of left and right lenses are colored.   The medical spectacles for a double vision or amblyopic patient according to any one of claims 1 to 6, wherein a mirror coat layer is formed on a surface of the pair of left and right lenses facing the object side.

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