Integrated apparatus for visual function testing and method thereof
This disclosure discloses an apparatus and method thereof for a comprehensive visual function testing apparatus. A plurality of visual test stimuli may be spatiotemporally sequenced and presented to the subject undergoing visual function tests including, but not limited to, visual acuity test, stereoscopic vision test, field of vision test and contrast sensitivity test. Furthermore, by combining all the elements under the same computational device, it streamlines the conventional visual function testing process, provides automated visual function testing of subjects, and refraction correction when required, such as for perimetry testing. Such an apparatus opens up unprecedented possibilities for refining the visual function testing process. High degree of integration resulting from adoption of the features disclosed, a variety of compact, portable, wearable embodiments may be achieved.
1 . An apparatus for conducting one or more tests of a subject's vision, the apparatus configured for being worn by a subject, and the apparatus comprising:
a display device for displaying a visual stimulus;
a feedback unit for receiving a response of the subject to the visual stimulus and conveying the response to a computational device;
a tunable lens; and
a retractable periscopic arm arrangement comprising mirrors configured to enable visual observation of the subject's eyes by an operator during a setup phase, for observing an inter-pupillary distance of the subject's eyes and for co-axially aligning a position of the tunable lens with the subject's eyes, the retractable periscopic arm arrangement being movable between a deployed position for the visual observation during the setup phase and a retracted position during vision testing,
wherein the computational device is configured for:
controlling the display device for displaying the visual stimulus to the subject for the subject to view through the tunable lens;
determining one or more characteristics of the vision of the subject based on the subject's response conveyed through the feedback unit;
tuning characteristics of the tunable lens based on the determined one or more characteristics of the vision of the subject; and
outputting values of the determined one or more characteristics of the vision of the subject.
2 . The apparatus of claim 1 , further comprising:
a proximity sensor communicatively coupled to the computational device; and
a projector communicatively coupled to the computational device,
wherein the computational device is further configured for:
measuring a distance between the subject and a passive screen in front of the subject and distant from the subject, based on an output of the proximity sensor; and
controlling the projector for projecting the visual stimulus on the passive screen, wherein a size of the visual stimulus projected is proportional to the measured distance between the subject and the passive screen.
3 . The apparatus of claim 1 , wherein the tunable lens is an electrically tunable lens, the characteristics of which are alterable by applying voltages to electrodes.
4 . The apparatus of claim 2 , further comprising a light sensor for measuring an ambient light intensity for conveying intensity data to the computational device, wherein the computational device is further configured for controlling brightness of the visual stimulus projected on the passive screen by the projector proportional to the ambient light intensity, brightness of a projected display being appropriate for determining the one or more characteristics of the vision of the subject.
5 . The apparatus of claim 2 , further comprising a light sensor for measuring a light intensity on the passive screen for conveying intensity data to the computational device, wherein the computational device is further configured for controlling brightness of the visual stimulus projected on the passive screen by the projector proportional to the light intensity on the passive screen, brightness of a projected display being appropriate for determining the one or more characteristics of the vision of the subject.
6 . The apparatus of claim 1 , wherein the visual stimulus is one or more visual stimuli selected from a group of stimuli comprising stimulus for testing a field of vision, a visual acuity, a contrast sensitivity, a color vision, a binocular function, a visual search, a glare and light/dark adaptation, and a visual efficiency.
7 . A method for conducting one or more tests of a subject's vision, wherein a subject is wearing an apparatus configured for being worn by the subject, the method comprising:
a step of displaying a visual stimulus on a display device of the apparatus, by a computational device of the apparatus, for viewing through a tunable lens of the apparatus, by the subject;
a step of conveying, to the computational device, the subject's response to the visual stimulus, by a feedback unit of the apparatus, configured for receiving the subject's response to the visual stimulus;
a step of enabling visual observation, by mirrors of a retractable periscopic arm arrangement of the apparatus, of the subject's eyes by an operator during a setup phase, for observing an inter-pupillary distance of the subject's eyes and for co-axially aligning a position of the tunable lens with the subject's eyes, the retractable periscopic arm arrangement being movable between a deployed position for the visual observation during the setup phase and a retracted position during vision testing;
determining, by the computational device, one or more characteristics of the vision of the subject based on the subject's response conveyed through the feedback unit; and
a step of outputting values of a refraction error and the determined one or more characteristics of the subject's vision.
8 . The method of claim 7 , wherein the visual stimulus is one or more visual stimuli selected from a group of stimuli comprising a stimulus for testing field of vision, a visual acuity, a contrast sensitivity, a color vision, a binocular function, a visual search, a glare and light/dark adaptation, and a visual efficiency.
9 . The method of claim 7 , wherein the visual stimulus for refraction testing includes projecting on a passive screen, located at a distance from the subject and in front of the subject, by a projector of the apparatus, and wherein a size of the visual stimulus is proportional to the distance between the passive screen and the subject.
10 . The method of claim 7 , further comprising a step of adjusting a brightness of the visual stimulus proportional to an ambient light intensity measured by a light sensor of the apparatus.