ES2244276A1 - Flat meter for assessing aniseikonia has lens system that fuses two images seen by eyes of subject - Google Patents

Abstract

Mounts are arranged near a polarizer to introduce a prismatic component and neutralize fixation disparity or phoria. The two images seen by each eye of a subject are fused together by a lens system.Flat eikonometer and procedure for obtaining the associated phoria. This invention consists of a device that can measure the aniseikonia of an observer with and without associated phoria compensation. Thus by making use of a polarising mechanism the subject can see a different optotype for each eye and close to these are some mountings onto which the prismatic value that neutralises the fixation disparity or associated phoria can be inserted. The aniseikonia can be measured with the two images fused and with the aid of a set of iseikonic lenses of known graduation.

Description

Flat eikonometer and procedure for Obtaining the associated foria.

Object of the invention

The present invention consists of a device able to measure aniseikonia in an observer canceling the foria associated or disparity of fixation thereof.

Background in the state of the art

The devices that exist today to measure aniseikonia are diverse and have been proposed different instruments since the 60s depending on the technology used in image fusion. Thus, there are different patents (US2002159169, US4427272, US2364844, SU1773378, SU1759419, SU1648337, SU1514340, DE4091126, DE4091126, DE3111665) that incorporate advances in progressive lenses, polarization, three-dimensional vision, etc. However, the state of the art in matter does not provide a device that determines aniseikonia compensating the associated foria, a parameter that masks the value real aniseikonia and it is necessary to cancel to provide a real measure of it.

Explanation of the invention.

The flat eikonometer and its procedure for obtaining associated foria is a device capable of measuring the aniseikonia of an observer with and without compensation of foria associated from a flat optotype that is illuminated by a conventional lighting source. Thus, the image reflected in the optotype is polarized and two polarizing sheets are included for that the fusion of the two different fields be partially allowed. Close to the chin guard where the observer rests and fixes the head, there are some frames for each eye that allow you to enter the desired prisms that cancel the fixation or foria disparity associated. Finally they are also incorporated, in the same mount, iseikonic lenses that cancel aniseikonia. The increase value of these lenses is the value of aniseikonia.

Thus, the subject observes a different optotype for each eye through the polarizing mechanism and locating near the eyes the frames in which the value can be entered prismatic that neutralizes the disparity of fixation or foria associated, when merging the two images the measurement of the aniseikonia with the reading of the magnification of the lenses iseikonics.

Description of the figures

In order to present an embodiment of the invention are presented below a figure in which represents in a practical way the embodiment of the invention described.

Figure (1): Eikonometer general scheme plan and procedure for obtaining associated foria. ''

In said figure, the numbered elements are relate below:

(one):

Optotype

(2):

Lighting system

(3):

Polarizing blades

(4):

Prism

(5):

Diaphragms

(6):

Eyes

(7):

Iseiconic lenses

Description of a preferred embodiment

A preferred embodiment of the invention is you can build from a box that contains the elements that They are shown in Figure 1 and described below.

First of all an optotype (1) consisting of horizontal and vertical marks with numbers on the sides. On top of the optotype (1) two polarizing sheets are placed with perpendicular polarizations, so that the light coming from the lighting system (2) reflected through the projector have Two different polarizations. To merge the images are used two polarizing blades (3) incorporated into frames. A number shifting when merging images is indicative of the condition of aniseikonia. To cancel the fixing disparity the system allows to incorporate in the frames the prisms (4) with the corresponding prismatic value. Sayings Prisms (4) are placed in the diaphragms (5). Perceived simultaneously the images already without associated foria in any of both eyes (6), iseiconic lenses (7) are added until the number marks are equalized in position. The magnitude of magnification of the corresponding lenses (7) provides the value of Aniseikonia with foria compensation.

Claims (4)

1. Flat eikonometer characterized by being constituted by an optotype (1) consisting of horizontal and vertical marks with numbers on the sides, the lighting system (2), two polarizing sheets located above the optotype and perpendicular polarizations so that the light coming from the lighting system (2) reflected through the projector has two different polarizations, two polarizing plates (3) to fuse the image incorporated into a frame that also contains prisms (4) of known prismatic value, diaphragms (5) to accommodate prisms (4) and iseiconic lenses (7) of known values. 2. Flat eikonometer according to claim 1, characterized by performing the measurement on a two-phase observer; a first determination of the associated foria, followed by a determination of its aniseikonia canceling the previously identified foria. 3. Procedure for obtaining associated foria, characterized in that in the flat eikonometer a displacement of the numbers when merging the images is indicative of the condition of aniseikonia progressively incorporates the prisms (4) with the prismatic value in the frames corresponding until the fixing disparity or associated foria is completely canceled. 4. Procedure for obtaining associated foria according to claim 3, characterized in that for obtaining the value of aniseikonia with foria compensation, iseiconic lenses (7) are added until the number marks are equalized in position. The magnitude of magnification of the corresponding lenses (7) provides the value of aniseikonia with foria compensation.