Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Subjective type
Reexamination Certificate
1999-07-16
2001-03-20
Manuel, George (Department: 3737)
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Subjective type
Reexamination Certificate
active
06203157
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method for testing a visual function (visual acuity and color function) using a display device; and, more particularly, to a method for improving accuracy of the visual function testing and reducing human resources in testing the visual function of an examinee.
DESCRIPTION OF THE PRIOR ARTS
Generally, the conventional visual acuity testing has used the printed visual acuity testing targets (hereinafter, referred to as eyesight testing targets) whose contents are fixed to different targets, such as number, characters and marks. However, in the case where an examinee bears them in mind, the results of the testing can not be reliable. Also, the visual acuity testing using a display device, which shows test patterns in such a manner as to provide only the printed eyesight testing targets, can not prevent the examinee from intentionally feigning his visual function.
Further, the conventional visual acuity testing has the examinee distinguish the eyesight testing targets in duplicate, which are classified by about 10 degrees up to 0.1 from 1.0, and then, the corresponding degree is considered as the examinee's visual acuity. Therefore, the tested visual acuity may not coincide with the examiner's actual degree and it is merely decided in the closest degree of the eyesight testing targets, thereby not precisely measuring the visual acuity.
Such a subjective visual acuity testing as above has a high probability to commit errors in the test result and a problem requiring extra manpower (e.g. nurse(s), doctor(s)) at the time of group test in hospital or school.
Meanwhile, in the conventional color function testing using color targets of “Ishihara” and “Cheon-Seok Han,” the examinee can memorize the color function discriminating targets (hereinafter, referred to as color-testing targets) in advance because the number of color targets is relatively small.
Further, “Han's color-testing targets” available for measuring the abnormality of an normal person in the color function testing makes it possible to measure his color function by just three degrees such as fine, medium and poor and “F-M 100-Hue” methods by which the abnormality degree can be more precisely measured should be carried out for a long time to decide the color function, thereby being inconvenient to practically use.
A method for measuring the abnormality degree by use of “Anomaloscope” requires peculiar high price of equipment and, in another method using color-testing targets printed on paper or “F-M 100-Hue” method measuring the degree by indicating the discriminating targets by hand, there is a problem that the colors of targets may be changed after passing a long time and thus, it is difficult to obtain precise result for the abnormality due to the changed colors of the targets.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a visual function testing method for easily performing the testing, heightening the precision of the testing by displaying the discrimination targets on a screen and deciding the examinee's vision function after evaluating the validity by the inputted data of the discriminated response from an examinee.
It is another object of the present invention to provide a visual function testing method for more precisely measuring a visual acuity by randomly producing the size, kinds, contrast, etc. of discrimination targets on a screen; taking the probability of subjective errors down by determining the invalidity of the test result and performing an automatic test based on examinee's discrimination response into a voice recognizing apparatus of the test device; producing visual-testing targets having predetermined size within the resolution range which the screen allows; and deciding the valid visual acuity by detecting the smallest size of the produced visual-testing targets.
It is further object of the present invention to provide a visual function testing method for more precisely measuring the color function testing by randomly producing the color-testing targets on a screen; preventing a feint of the test result by using the randomly produced color-testing targets; improving the probability of subjective errors of the test result; and providing the various degrees of difficulty within some ranges in displaying different hues or contrasts of color to be discriminated.
It is another object of the present invention to provide a visual function testing method for measuring precise result even by only several tests, by applying to the binary search for many discrimination targets necessary for precise measurement of the visual acuity testing or the color function testing.
According to an aspect of the present invention, there is provided a method for testing a visual function of an examinee using a computer system, the method comprising the steps of: a) selecting at least one target to be discriminated; b) producing the selected target on a screen of the computer system; c) inputting a response to the selected target from the examinee; d) ascertaining whether the response is right or wrong; e) repeatedly carrying out the steps of a) to d) in various degrees, comparing the responses to the repeatedly different targets and evaluating a validity of the visual function testing; and f) deciding the visual function of the examinee based on the evaluated validity.
According to another aspect of the present invention, there is provided a method for testing a color function of an examinee using a computer system, the method comprising the steps of: i) displaying at least one color-testing target which is differently discriminated by a normal person and protanope; ii) deciding the examinee to be a protanope if the examinee gives a response to the target, which is discriminated by a protanope; and iii) checking a degree of red blindness by using at least two targets having a different amount of a red component.
According to still another aspect of the present invention, there is provided a method for testing a visual function of an examinee using a computer system, the method comprising the steps of: 1) displaying on a screen a middle value target in a testing range from a lower limited value to a upper limited value; 2) inputting a response to the middle value target from the examinee; 3) ascertaining whether the response is right or wrong; and 4) deciding the examinee's visual acuity, comprising the steps of: 4-1) if the response is wrong, changing the upper limited value based on the middle value target and repeatedly carrying out the steps of 1) to 3); and 4-2) if the response is right, changing the lower limited value based on the middle value target and repeatedly carrying out the steps of 1) to 3).
REFERENCES:
patent: 4526452 (1985-07-01), Hirsch
Manuel George
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Tai Won Lee
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