Abstract:
A testing device and method are presented for detecting binocular vision problems in patients. The testing device includes a body with a flat portion disposed along one side. Extending outwardly from the top of the body is an actuating means. The device further includes a first set of lights disposed on the surface of the device a first distance away from a center point and a second set of lights disposed a second distance away from the center point. Each of the lights in the first set are smaller than each of the lights in the second set. Further, the second distance is shorter than the first distance.

Description:
RELATED APPLICATIONS 
     This patent application claims priority to prior copending provisional Application No. 61/032,843 filed Feb. 29, 2008, entitled Vision Testing Apparatus and Method, which is hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates generally to testing devices and procedures for binocular vision, and more particularly to those utilizing the Worth 4-dot test. 
     Binocular vision is the ability to maintain visual focus on an object with both eyes, creating a single visual image. When the brain fails to process the visual input received by one or the other of the eyes properly, one of the images may be suppressed causing a patient to experience distortions in depth perception and visual measurement of distance. Alternatively, the brain may fuse the images, causing the patient to suffer from double vision. 
     The loss of binocularity is primarily seen in patients with strabismus, with or without amblyopia. 
     SUMMARY 
     In one implementation, a device for testing for binocular vision is presented. The device includes a body having a flat portion along one side and an actuating means that extends outwardly from the top. The device further includes a first set of lights disposed on the surface of the device a first distance away from a center point. 
     In another implementation, a device for testing for binocular vision is presented. The device includes a body having a flat portion along one side and an actuating means that extends outwardly from the top. The device further includes a first set of lights disposed on the surface of the device a first distance away from a center point and a second set of lights disposed a second distance away from the center point. Each of the lights in the first set are smaller than each of the lights in the second set. Further, the second distance is shorter than the first distance. 
     Another implementation, a method of detecting binocular vision problems in a patient is presented. The method includes the use of a testing device having multiple lights disposed on a surface. The testing device is further capable of powering the lights at a plurality of brightness settings. The method includes supplying a pair of test glasses to the patient having different lenses. Next a first brightness setting is selected and the lights are exposed to the patient at the brightness setting. Finally, a result is determined. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like elements bear like reference numerals. 
         FIG. 1A  depicts a perspective view of an exemplary embodiment of Applicants&#39; test apparatus; 
         FIG. 1B  depicts a front view of an exemplary embodiment of Applicants&#39; test apparatus; 
         FIGS. 2A and 2B  are block diagrams showing exemplary embodiments of the components of Applicants&#39; test apparatus; 
         FIGS. 3A and 3B  are flow charts summarizing exemplary vision tests administered using Applicants&#39; test apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     This invention is described in preferred embodiments in the following description with reference to the Figures, in which like numbers represent the same or similar elements. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
     The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are recited to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
     The schematic flow charts included are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. 
     One test used to examine a patient&#39;s binocular vision is the “Worth 4-dot” test, also known as the “Worth dot” test. During the Worth 4-dot test, the patient wears anaglyphic glasses. Such glasses have one red lens, typically over the right eye, and one green lens, typically over the left eye. The patient is then shown a modified flashlight where the front is covered such that light is emitted only through four holes arranged in a diamond pattern. When the modified flashlight is positioned correctly, the top hole shows only red light, the left and right holes show only green light, and the bottom hole shows only white light. 
     The red lens of the anaglyphic glasses blocks the green light and the green lens blocks the red light, making it possible to determine if the patient is using both eyes simultaneously in a coordinated manner. When both eyes are open, a patient having normal vision will see all four lights. When the patient closes one eye, they will see either two or three lights depending on which eye is suppressed. If the patient suffers from diplopia (double vision) vision, he/she will see five lights. 
     One limitation of performing a Worth 4-dot test using a modified flashlight is that the flashlight must be positioned properly for the test to be accurate. Given a flashlight&#39;s uniform shape, it is easy for the test administrator to rotate the flashlight such that the holes are no longer positioned correctly, thereby giving inaccurate test results. Further, a flashlight can be cumbersome for the test administrator. 
     Another limitation of using the described flashlight to test for binocular vision is that it has only one power level and therefore one brightness setting. This can make it difficult, if not impossible, to quantify the degree of binocular vision the patient suffers from. Further, most flashlights are powered with D cell batteries that weaken over time, causing the power level, and therefore the brightness, to fluctuate in an uncontrolled manner. 
     In the illustrated embodiment of  FIGS. 1A and 1B , Applicants&#39; test apparatus  100  comprises a cylindrical housing  110  comprising a first end comprising a first surface  115  comprising a center point, and a second end comprising a second surface, wherein said cylindrical body is formed to include a flat portion  114  disposed between said first surface and said second surface. In certain embodiments, test apparatus  100  comprises a diameter  102  of between about 1.5 inches to about 3 inches. In certain embodiments, test apparatus  100  comprises a diameter  102  of about 2.5 inches. In certain embodiments, test apparatus  100  comprises a thickness  104  of between about 0.25 inches to about 1 inch. In certain embodiments, test apparatus  100  comprises a thickness  104  of about 0.5 inch. 
     Referring now to  FIG. 1B , testing apparatus  100  further comprises an actuating means  160  extending outwardly through housing  110  and into recessed portion  112 . In the illustrated embodiment of  FIG. 1B , actuating means  160  comprises a push button. In other embodiments, actuating means  160  comprises a switch. In yet other embodiments, actuating means  160  is electronic. In yet other embodiments, actuating means  160  is mechanical. 
     In the illustrated embodiment of  FIG. 1B , light emitting devices  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150  and  155  are disposed on surface  115 . In other embodiments, only light emitting devices  120 ,  130 ,  140 , and  150  are disposed on surface  115 . In certain embodiments, light emitting devices  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150  and  155  comprise light emitting diodes (“LEDs”). In certain embodiments, light emitting devices  120  and  125 , when active, emit red light. In certain embodiments, light emitting devices  130  and  135 , when active, emit green light. In certain embodiments, light emitting devices  140  and  145 , when active, emit green light. In certain embodiments, light emitting devices  150  and  155 , when active, emit white light. 
     In the illustrated embodiment of  FIG. 1B , light emitting devices  125 ,  135 ,  145 , and  155  are located at first distance and light emitting devices  120 ,  130 ,  140 , and  150  are located at a second distance from a center point on surface  115 . In certain embodiments, the first distance is one-quarter of the second distance. In certain embodiments, the first distance is 0.5 inch. In certain embodiments, the second distance is 1.5 inches. 
     A correct orientation of the colors displayed by the plurality of light emitting devices  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150  and  155  is critical to proper use. Housing  110  is shaped such that test device can be held in a user&#39;s right hand, with the thumb or palm resting on flat portion  114 , and an index or middle finger positioned on actuating means  160 . When holding test apparatus in either hand, if flat portion  114  is vertical, then test apparatus is correctly oriented such that the plurality of light emitting devices  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150  and  155  are viewed by the test subject, i.e. a patient, with the red light-emitting devices at the top and the white light-emitting devices at the bottom. 
     Referring to  FIG. 2A , in certain embodiments test apparatus  100  further comprises processor  210 , power source  220 , computer readable medium  230 , and computer readable program code  240 . Processor  210  utilizes instructions  240  to operate test apparatus  100 . Processor  210  is interconnected with actuating means  160  via communication link  205  and with memory  230  via communication link  215 . 
     In certain embodiments, processor  210 , memory  230 , and instructions  240 , comprise an integral assembly. In certain embodiments, processor  210 , memory  230 , and instructions  240 , comprise an application specific integrated circuit (“ASIC”). 
     Power source  220  supplies power to processor  210  and memory  230  via power buses  222  and  224 , respectively. Processor  210  is interconnected to light emitting device  120  via power bus  122 . Processor  210  is interconnected to light emitting device  130  via power bus  132 . Processor  210  is interconnected to light emitting device  140  via power bus  142 . Processor  210  is interconnected to light emitting device  150  via power bus  152 . When actuating means  160  is depressed to a first actuating point, processor  210  supplies power to light emitting devices  120 ,  130 ,  140 , and  150 . 
     Instructions  240  comprise power levels for (N) different brightness levels. Using a brightness level of 1, processor  210  supplies the smallest amount of power to light emitting devices  120 ,  130 ,  140 , and  150 . Using the (N)th brightness level, processor  210  supplies the greatest amount of power to light emitting devices  120 ,  130 ,  140 , and  150 . In embodiments wherein light emitting devices  120 ,  130 ,  140 , and  150 , comprise LEDs, processor  210  varies the current supplied to those LEDS as a function of (i), wherein (i) is greater than or equal to 1 and less than or equal to (N). 
     Referring to  FIG. 2B , in certain embodiments, processor  210  is interconnected to light emitting device  125  via power bus  124 . Processor  210  is interconnected to light emitting device  135  via power bus  134 . Processor  210  is interconnected to light emitting device  145  via power bus  144 . Processor  210  is interconnected to light emitting device  155  via power bus  154 . When actuating means  160  is depressed to a second actuating point, processor  210  supplies power to light emitting devices  125 ,  135 ,  145 , and  155 . 
     Instructions  240  further comprise power levels for (P) different brightness levels. Using a brightness level of 1, processor  210  supplies the smallest amount of power to light emitting devices  125 ,  135 ,  145 , and  155 . Using the (P)th brightness level, processor  210  supplies the greatest amount of power to light emitting devices  125 ,  135 ,  145 , and  155 . In embodiments wherein light emitting devices  125 ,  135 ,  145 , and  155 , comprise LEDs, processor  210  varies the current supplied to those LEDS as a function of (j), wherein (j) is greater than or equal to 1 and less than or equal to (P). 
       FIG. 3A  summarizes the steps of an exemplary vision test administered to a patient using Applicants&#39; test apparatus  100 . Referring now to  FIG. 3A , in step  302  the method supplies Applicants&#39; test apparatus  100  and a pair of test glasses comprising one red lens and one green lens, wherein the red lens covers the patient&#39;s right eye and the green lens covers the patient&#39;s left eye. 
     In step  304 , the method selects the number of brightness levels to employ. In certain embodiments, (N) is one. In these embodiments, Applicant&#39;s apparatus  100  does not comprise a processor or memory. Rather in the (N)=1 embodiments, the actuating means  160  comprises a switch which, when depressed to a first actuating position, supplies power to each of light emitting devices  120 ,  130 ,  140 , and  150 . 
     In embodiments wherein test apparatus  100  comprises a processor and memory, and wherein (N) is greater than 1, the tester can elect to only use one of those (N) brightness levels. In these embodiments, the tester first repeatedly depresses actuating means  160  to the first actuating position until the desired brightness level is reached. 
     In step  306 , the tester holds test apparatus  100  in one hand as described hereinabove and depresses actuating means  160  to the first actuating position. In step  308 , the tester selects an (i)th brightness setting, wherein (i) is initially set to one. 
     In one embodiment, the tester holds the test apparatus forty-five (45) centimeters from the patient. In other embodiment, the tester varies the distance the test apparatus is from the patient to access the size of the area of suppression of the patient&#39;s visual field. 
     In step  310 , the method records the number of lights the patient reports seeing while wearing the test glasses with the green lens covered. Using only the right eye seeing through the red lens, the patient should see two lights, namely the red light and the white light. 
     In step  312 , the method records the number of lights the patient reports seeing while wearing the test glasses with the red lens covered. Using only the left eye seeing through the green lens, the patient should see three lights, namely the two green lights and the white light. 
     In step  314 , the method records the number of lights the patient reports seeing while wearing the test glasses with neither lens covered. Using both eyes, the patient should see all four lights. 
     In step  316 , the method records the number of lights the patient reports seeing without the test glasses. With both eyes open and no test glasses, the patient should see four lights if the patient has focused binocular vision. If the patient sees 5 lights using both eyes, then the patient does not have proper binocular vision, and likely suffers from double vision. 
     In step  318 , the method determines if all the brightness levels have been tested, i.e. if (i) equals (N). If all brightness levels have been tested, then the method transitions from step  318  to step  322  and ends. Alternatively, if the method determines in step  318  that (i) does not equal (N), then the method transitions from step  318  to step  320  wherein (i) is incremented by unity, i.e. (i) is set to (i+1). The method transitions from step  320  to step  308  and continues as described herein. In certain embodiments, steps  320  and  322  comprise depressing actuating means  160  to a first actuating position, wherein processor  210  increases the power supplied to each of light emitting devices  120 ,  130 ,  140 , and  150 . 
       FIG. 3B  summarizes the steps of another exemplary vision test administered to a patient using Applicants&#39; test apparatus  100 . Referring now to  FIG. 3B , in step  324  the method supplies Applicants&#39; test apparatus  100  and a pair of test glasses comprising one red lens and one green lens, wherein the red lens covers the patient&#39;s right eye and the green lens covers the patient&#39;s left eye. 
     In step  326 , the method selects the number of brightness levels to employ. In certain embodiments, (P) is one. In these embodiments, Applicant&#39;s apparatus  100  does not comprise a processor or memory. Rather in the (P)=1 embodiments, the actuating means  160  comprises a switch which, when depressed to a second actuating position, supplies power to each of light emitting devices  125 ,  135 ,  145 , and  155 . 
     In embodiments wherein test apparatus  100  comprises a processor and memory, and wherein (P) is greater than 1, the tester can elect to only use one of those (P) brightness levels. In these embodiments, the tester first repeatedly depresses actuating means  160  to the second actuating position until the desired brightness level is reached. 
     In step  328 , the tester holds test apparatus  100  in one hand as described hereinabove and depresses actuating means  160  to the second actuating position. In step  330 , the tester selects an (j)th brightness setting, wherein (j) is initially set to one. 
     In one embodiment, the tester holds the test apparatus at approximately twenty-five (25) centimeters from patient to drive the patient&#39;s eyes together to see the same object. 
     In step  332 , the method records the number of lights the patient reports seeing while wearing the test glasses with the green lens covered. Using only the right eye seeing through the red lens, the patient should see two lights, namely the red light and the white light. 
     In step  334 , the method records the number of lights the patient reports seeing while wearing the test glasses with the red lens covered. Using only the left eye seeing through the green lens, the patient should see three lights, namely the two green lights and the white light. 
     In step  336 , the method records the number of lights the patient reports seeing while wearing the test glasses with neither lens covered. Using both eyes, the patient should see all four lights. 
     In step  338 , the method records the number of lights the patient reports seeing without the test glasses. With both eyes open and no test glasses, the patient should see four lights if the patient has focused binocular vision. If the patient sees 5 lights using both eyes, the patient&#39;s suffers from double vision. 
     In step  340 , the method determines if all the brightness levels have been tested, i.e. if (j) equals (P). If all brightness levels have been tested, then the method transitions from step  340  to step  344  and ends. Alternatively, if the method determines in step  340  that (j) does not equal (P), then the method transitions from step  340  to step  342  wherein (j) is incremented by unity, i.e. (j) is set to (j+1). The method transitions from step  342  to step  330  and continues as described herein. In certain embodiments, steps  342  and  344  comprise depressing actuating means  160  to a second actuating position, wherein processor  210  increases the power supplied to each of light emitting devices  125 ,  135 ,  145 , and  155 . 
     In certain embodiments, individual steps recited in  FIGS. 3 and 4 , may be combined, eliminated, or reordered. 
     In certain embodiments, Applicants&#39; invention includes instructions, such as computer readable program code  240  ( FIG. 2A ), residing in computer readable medium, such as for example computer readable medium  230  ( FIG. 2A ) wherein those instructions are executed by a processor, such as processor  210  ( FIG. 2A ), to perform one or more of steps recited in  FIG. 3A , and/or one or more of steps recited in  FIG. 3B . 
     While the preferred embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention.