Angle observation lens using multiple prism lenses

Abstract

To provide a lens with which a preferable angle image can be obtained without largely inclining an eyeball or a microscope in angle observation of the field of ophthalmology.SOLUTION: High refractive prism lenses 1, 2, and 3 including a convex surface and a concave surface are combined with a separate lens, an air layer is provided in between the lens 2 and the lens 3, and the lens 2 is made to be an inverted prism having a small Abbe number, so that a clear angle image of a large field of view and with less color aberration can be obtained while maintaining magnification without largely inclining an eyeball or a microscope.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an angle observation lens that strongly refracts observation light by sandwiching an air layer between a plurality of prism lenses, thereby facilitating observation. [Background technology]

[0002] In the field of ophthalmology, the angle observation lenses used in glaucoma surgery mainly use a single prism lens. In recent years, lenses using two mirrors have come to be used instead of prism lenses. Problems to be solved by the invention

[0003] However, a single prism lens does not bend light sufficiently, and in order to observe the angle between the cornea and the iris, the patient's eyeball and the surgical microscope must be tilted significantly, which makes the surgery less maneuverable. In addition, the stronger the prism lens bends light, the more chromatic aberration causes the image to become unclear, which is a problem. On the other hand, a lens using two mirrors does not require the eyeball or microscope to be tilted, and there is no chromatic aberration, but it has the disadvantage that the image is reduced due to the longer optical path, and it is expensive due to its complex structure. Means to solve the problem

[0004] In order to solve the above problem, the present invention combines multiple prism lenses with a layer of air between them. By passing through the boundary surface between the lens and air, which has a large difference in refractive index, many times, it is possible to strongly refract the observation light.

[0005] This invention allows observation of the iridocorneal angle without significantly tilting the eyeball or the microscope. In addition, the optical path is not lengthened and the image size can be secured. Furthermore, by adding an inverted prism lens with a small Abbe number, chromatic aberration can be minimized and a clear image can be obtained. Since it is composed only of prism lenses, it can be produced relatively inexpensively. [Brief description of the drawings]

[0006] [Figure 1]FIG. 2 is a cross-sectional view of the present invention. [Diagram 2] 1 is a cross-sectional view with lines added showing the change in a parallel beam of observation light as it passes through the inside of the present invention and the eyeball and reaches the angle of the eye when the present invention is in use. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an embodiment of the present invention, in which three cylindrical high-refractive-index glass pieces (1, 2, 3) with a diameter of 11.2 mm are cut along a plane perpendicular to the cross-section and then assembled. FIG. 2 shows the state in which the lens is actually placed on the eyeball and the parallel beam of observation light is bent. The lens [3] (3) is placed on the cornea (4) of the eyeball to be observed, and the observer observes from the lens [1] (1) side. The bottom surface of the lens [3] is a concave lens to fit the shape of the cornea, and the observation surface of the lens [1] is a convex lens to offset the reduction in the image caused by this. The lens [2] (2) is made of glass with a small Abbe number, and acts as a prism lens in the opposite direction to the lenses [1] and [3], reducing chromatic aberration. The layer of air between the lenses [2] and [3] realizes a strong bending of light that is not possible with a single prism lens. Figure 2 is designed to provide a wide view of the iris (5) and the angle (6), but the observable range and magnification can be designed to vary depending on the refractive index and shape of the lenses used and the distance between each lens. [Explanation of symbols]

[0008] 1 Lens[1] 2 Lenses[2] 3 Lenses[3] 4 Cornea 5. Iris 6 Corner 7. Observation light flux

Claims

[Claim 1] This is an angle observation lens in which a plurality of prism lenses having a function of bending observation light are combined with an air layer between them, making it possible to bend strong observation light as a whole, and which can be attached to the cornea.

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