A waveguide apparatus includes a planar waveguide and at least one optical diffraction element (DOE) that provides a plurality of optical paths between an exterior and interior of the planar waveguide. A phase profile of the DOE may combine a linear diffraction grating with a circular lens, to shape a wave front and produce beams with desired focus. Waveguide apparati may be assembled to create multiple focal planes. The DOE may have a low diffraction efficiency, and planar waveguides may be transparent when viewed normally, allowing passage of light from an ambient environment (e.g., real world) useful in AR systems. Light may be returned for temporally sequentially passes through the planar waveguide. The DOE(s) may be fixed or may have dynamically adjustable characteristics. An optical coupler system may couple images to the waveguide apparatus from a projector, for instance a biaxially scanning cantilevered optical fiber tip.

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.

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.

A spectrally adjustable ocular photosensitivity analyzer (SAOPA) is capable of emulating light sources common in everyday environments. An array of multiple light sources generates the desired spectra at intensities that are sufficient to elicit an uncomfortable level of photostress or light discomfort in normal human subjects sufficient to identify, and preferably quantify, a visual photosensitivity threshold of a human subject.

A spectrally adjustable ocular photosensitivity analyzer (SAOPA) is capable of emulating light sources common in everyday environments. An array of multiple light sources generates the desired spectra at intensities that are sufficient to elicit an uncomfortable level of photostress or light discomfort in normal human subjects sufficient to identify, and preferably quantify, a visual photosensitivity threshold of a human subject.

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.

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.

A method for facilitating surgery using an augmented reality system, comprises retrieving patient data relating to a surgical procedure on a patient, generating virtual content comprising a virtual three-dimensional (3D) anatomical model based on the patient data, and displaying the virtual content, such that, when viewed by the first user, the virtual 3D anatomical model appears to be fixed at a physical location, whereby the virtual 3D anatomical model may be viewed by the first user from any angle or orientation merely by walking around the physical location.

A method for facilitating surgery using an augmented reality system, comprises retrieving patient data relating to a surgical procedure on a patient, generating virtual content comprising a virtual three-dimensional (3D) anatomical model based on the patient data, and displaying the virtual content, such that, when viewed by the first user, the virtual 3D anatomical model appears to be fixed at a physical location, whereby the virtual 3D anatomical model may be viewed by the first user from any angle or orientation merely by walking around the physical location.

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.