Visual field test in a VR headset
Virtual reality, VR, headset-based electronic systems that can be used to perform visual field tests. The systems may improve the sensitivity, consistency, and case of application of the visual field test. Other aspects are also described.
1 . A system adapted to perform visual field testing, the system comprising:
a headset comprising:
a left visible light display;
a left compartment to fit over a left eye of a user;
a right visible light display;
a right compartment to fit over a right eye of the user, wherein the left and right compartments are configured so that when the headset has been fitted over the user's eyes i) the user cannot see the right visible light display using only their left eye and ii) the user cannot see the left visible light display using only their right eye, and
a non-visible light-based eye tracking subsystem that produces tracking data for the left eye or for the right eye; and
a processor configured to, when the headset has been placed to the user's eyes:
i) signal the left or right visible light display to display a fixation target, and then a stimulus target simultaneously with the fixation target;
ii) determine a stimulus angle of a stimulus vector that points from the fixation target to the stimulus target;
iii) use the tracking data from the eye tracking subsystem to record a tracked position of the right eye or a tracked position of the left eye as the right eye or the left eye moves when the stimulus target appears in i);
iv) interpret the tracked position of the right eye or the left eye to determine a response angle of a response vector that points in a direction in which the right eye or the left eye has moved;
v) record an indication as to whether the user has seen the stimulus target, based on a comparison between the stimulus angle and the response angle; and
vi) map a visual field of the user based on the indication recorded for different locations of the stimulus target.
2 . The system of claim 1 wherein the stimulus angle is predetermined in a laboratory or factory.
3 . The system of claim 1 wherein the stimulus angle is computed by the processor online.
4 . The system of claim 1 wherein the processor computes the stimulus vector and then determines the stimulus angle by processing the stimulus vector.
5 . The system of claim 1 wherein the processor computes the response vector and then determines the response angle by processing the response vector.
6 . The system of claim 1 wherein mapping the visual field of the user comprises the processor repeating i)-v) a plurality of times each time with the stimulus target at one of the different locations, to cover the visual field of the user for purposes of completing a visual field test on the left eye or the eye of the user.
7 . The system of claim 6 wherein the processor completes the visual field test on the user without receiving manual or verbal input from the user on whether the user has seen the stimulus target each time.
8 . The system of claim 6 wherein each time the processor performs i)-v), the fixation target remains stationary.
9 . The system of claim 6 wherein each time the processor performs i)-v), a location of the fixation target changes.
10 . The system of claim 1 wherein the indication is that the user has seen the stimulus target and is based on the processor computing a difference between the stimulus angle and the response angle which is less than a threshold.
11 . The system of claim 1 wherein the processor determines the stimulus vector as defined by the stimulus angle and by a stimulus magnitude, and determines the response vector as defined by the response angle and a response magnitude, and the indication as to whether the user has seen the stimulus target is further based on the processor determining whether the response magnitude is i) greater than a noise threshold and ii) within a range of the stimulus magnitude.
12 . The system of claim 1 wherein the processor determines the stimulus vector as defined by the stimulus angle and by a stimulus magnitude and determines the response vector as defined by the response angle and a response magnitude, and the indication as to whether the user has seen the stimulus target is further based on the processor comparing the response magnitude with the stimulus magnitude.
13 . The system of claim 6 wherein the processor completes the visual field test on the user without receiving manual input from the user on whether the user has seen stimulus target at each of the plurality of distinct locations.
14 . A system adapted to perform visual field testing, the system comprising:
a headset comprising:
a left visible light display;
a left compartment to fit over a left eye of a user;
a right visible light display;
a right compartment to fit over a right eye of the user, wherein the left and right compartments are configured so that when the headset has been fitted over the user's eyes i) the user cannot see the right visible light display using only their left eye and ii) the user cannot see the left visible light display using only their right eye, and
a head tracking subsystem that produces tracking data; and
a processor configured to, when the headset has been placed to the user's eyes:
i) signal the left or right visible light display to display a fixation target, and then a stimulus target simultaneously with the fixation target;
ii) determine a stimulus angle of a stimulus vector that points from the fixation target to the stimulus target;
iii) use the tracking data from the head tracking subsystem to record a tracked position or tracked orientation of a head of the user when the stimulus target appears in i);
iv) interpret the tracked position or tracked orientation of the head to determine a response angle of a response vector that points in a direction in which the head has moved;
v) record an indication as to whether the user has seen the stimulus target, based on a comparison between the stimulus angle and the response angle; and
vi) map a visual field of the user based on the indication recorded for different locations of the stimulus target.
15 . The system of claim 14 wherein the stimulus angle is predetermined in a laboratory or factory.
16 . The system of claim 14 wherein the stimulus angle is computed by the processor online.
17 . The system of claim 14 wherein the processor computes the stimulus vector and then determines the stimulus angle by processing the stimulus vector.
18 . The system of claim 14 wherein the processor computes the response vector and then determines the response angle by processing the response vector.
19 . A system comprising:
a headset comprising:
a left visible light display;
a left compartment to fit over a left eye of a user;
a right visible light display;
a right compartment to fit over a right eye of the user, wherein the left and right compartments are configured so that when the headset has been fitted over the user's eyes i) the user cannot see the right visible light display using only their left eye and ii) the user cannot see the left visible light display using only their right eye, and
a non-visible light-based eye tracking subsystem that produces tracking data for the left eye or for the right eye; and
a processor coupled to memory storing instructions that, when executed by the processor, cause the system to perform operations including:
i) signaling the left or right visible light display to display a fixation target, and then a stimulus target simultaneously with the fixation target;
ii) determining a stimulus angle of a stimulus vector that points from the fixation target to the stimulus target;
iii) using the tracking data from the eye tracking subsystem to record a tracked position of the right eye or a tracked position of the left eye as the right eye or the left eye moves when the stimulus target appears in i);
iv) interpreting the tracked position of the right eye or the left eye to determine a response angle of a response vector that points in a direction in which the right eye or the left eye has moved; and
v) recording an indication as to whether the user has seen the stimulus target, based on a comparison between the stimulus angle and the response angle,
wherein the indication is that the user has seen the stimulus target and is based on the processor computing a difference between the stimulus angle and the response angle which is less than a threshold.