An analysis unit determines at least two boundaries by determining; in a coordinate system indicating a correlation between a luminance contrast value between a luminance of an attention portion and a luminance of a background portion, and a luminance average value of a visual target including the attention portion and the background portion; the boundary between a region where a subject has a visibility and a region where the subject does not have the visibility for each combination of stimulus values of a color stimulus of a visual target.

An analysis unit determines at least two boundaries by determining; in a coordinate system indicating a correlation between a luminance contrast value between a luminance of an attention portion and a luminance of a background portion, and a luminance average value of a visual target including the attention portion and the background portion; the boundary between a region where a subject has a visibility and a region where the subject does not have the visibility for each combination of stimulus values of a color stimulus of a visual target.

One embodiment is directed to a system comprising a head-mounted member removably coupleable to the user's head; one or more electromagnetic radiation emitters coupled to the head-mounted member and configured to emit light with at least two different wavelengths toward at least one of the eyes of the user; one or more electromagnetic radiation detectors coupled to the head-mounted member and configured to receive light reflected after encountering at least one blood vessel of the eye; and a controller operatively coupled to the one or more electromagnetic radiation emitters and detectors and configured to cause the one or more electromagnetic radiation emitters to emit pulses of light while also causing the one or more electromagnetic radiation detectors to detect levels of light absorption related to the emitted pulses of light, and to produce an output that is proportional to an oxygen saturation level in the blood vessel.

An apparatus (100, 200, 300, 400) for testing a subject's vision and a method of reducing intensity artefacts during a test of a subject's eye (109) are provided. The apparatus comprises: a light source arrangement (102) located towards a source end (104) of the apparatus, and arranged to produce polarized light; and one or more panels (108a, 108b, 108c), the one or more panels comprising one or more blocking regions that do not transmit polarized light, and defining one or more light transmitting regions (111), the one or more light transmitting regions (111) being just large enough to allow unobscured vision by the subject's eye of polarized light travelling directly from the light source arrangement when the subject's eye is positioned adjacent to a viewing end (106) of the apparatus, the one or more panels being located between the light source arrangement and the subject's eye.

An apparatus (100, 200, 300, 400) for testing a subject's vision and a method of reducing intensity artefacts during a test of a subject's eye (109) are provided. The apparatus comprises: a light source arrangement (102) located towards a source end (104) of the apparatus, and arranged to produce polarized light; and one or more panels (108a, 108b, 108c), the one or more panels comprising one or more blocking regions that do not transmit polarized light, and defining one or more light transmitting regions (111), the one or more light transmitting regions (111) being just large enough to allow unobscured vision by the subject's eye of polarized light travelling directly from the light source arrangement when the subject's eye is positioned adjacent to a viewing end (106) of the apparatus, the one or more panels being located between the light source arrangement and the subject's eye.

An anomaloscope comprises a display and a controller of the display. The display has pixels arranged in a plurality of groups, each group containing at least three pixels, each pixel being capable of emitting monochromatic light at a distinct wavelength. The controller of the display causes the display to emit, in at least one of the plurality of groups, light at a first wavelength and causes the display to emit, in at least another one of the plurality of groups, light at two other wavelengths. The controller of the display controls intensities of the light emitted at each of the distinct wavelengths to generate of a pair of metameric colors between the light emitted at the first wavelength and a combination of the light emitted at the two other wavelengths. A method uses the anomaloscope to assess an ability of a subject to discriminate between colors.

Methods, apparatus, and systems for performing an ophthalmic diagnostic test are disclosed. In one aspect, a head-wearable device for administering an ophthalmic test to a subject can comprise a head-wearable frame for mounting the device onto the subject's head, and a light seal configured for coupling to the frame so as to isolate at least one eye of the subject from ambient light when the device is worn by the subject.

Systems and methods for determining whether to enable color blind accessibility settings within the course of a user interactive narrative are described herein. Virtual color blindness indication objects containing colors that are visibly distinguishable within a single dichromatic visual spectrum can be utilized in objectives to determine a user's dichromatic visual deficiency type.

An optometry device for testing an individual's eye includes: a casing; an imaging module located in the casing and adapted to produce a light beam directed to the individual's eye; and a refraction module adapted to provide a variable optical correction to the individual's eye looking there through into the casing. The optometry device includes an illumination system adapted to produce a variable ambient light level inside the casing.

In some embodiments, initial feedback indicating threshold characteristics (under which a user sees initial stimuli presented on a user interface) may be provided to a prediction model, and a set of predicted characteristics (for a set of locations of the user interface) and a set of confidence scores associated with the set of locations may be obtained via the prediction model. Based on the set of confidence scores, one or more locations may be selected to be tested during a visual test presentation. As an example, the locations may be selected over one or more other locations of the set of locations based on the set of confidence scores. Based on predicted characteristics associated with the selected locations, stimuli may be presented at the selected locations during the visual test presentation. Visual defect information for the user may be generated based on feedback from the visual test presentation.