The invention relates to a handheld aesthesiometer, comprising a gas lung connected with intermediation from first valve means to a source of gas and comprising an expandable cavity intended to house a volume of gas in a loading phase of the aesthesiometer; an outlet nozzle connected to the gas lung with intermediation from second valve means and suitable for directing a puff of the volume of the gas housed in the gas lung in a firing phase of the aesthesiometer; and a mechanism to ensure in the aforementioned firing phase of the aesthesiometer the release of the puff of the volume of gas contained in the gas lung in the direction of the outlet nozzle by means of a controlled contraction of the expandable cavity of the gas lung in order to ensure a substantially constant outlet pressure.

The eye examination kiosk and method may comprise a structure for rotating and/or translating ophthalmologic examination devices such as an auto-refractor, an auto-keratometer, a corneal topographer, a fundus camera, an external photo camera, a perimeter, a lensmeter, a specular microscope, a retinal and external eye imager, an Optical Coherence Tomographer (OCT), or a non-contact tonometer into a position such that they may be used for examination of a patient. The kiosk outer shell may comprise an opening allowing the ophthalmologic examination equipment to perform eye examinations of a patient. Eye examination results are transmitted to a remote location where they are read by a physician, who transmits examination findings and recommendations for follow up treatment to the patient. The results may include the identity of qualified physicians who practice geographically near the patient, or who are qualified to treat a patient for a specific condition indication.

In a slit lamp microscope, ease of maintenance of an illumination-power-supply cable is improved while preventing the cable from appearing untidy. An illumination support arm of a slit lamp microscope is provided with a groove-shaped cable holder in which the illumination-power-supply cable is disposed along the outer surface of the illumination support arm in an externally exposed state. This configuration facilitates replacement of the illumination-power-supply cable even when a problem, such as breaking of the illumination-power-supply cable, occurs, thus improving ease of maintenance. Furthermore, because the illumination-power-supply cable is disposed along the groove-shaped cable holder, the slit lamp microscope has a neat appearance.

An alignment means of a measurement instrument includes a housing an optical component having a principal axis in a direction parallel to a desired alignment; a first light source positioned at a first distance S1 from the optical component and at a first height h1 from the principle axis; a second light source positioned at a second distance S2 from the optical component and at a second height h2 from the principle axis; and an angle barrier means arranged between the optical component, and the first and second light sources. The housing, the optical component, and the angle barrier means are arranged to block visibility of the first light source along the principal axis at a distance superior to d1′; and block visibility of the second light source along the principal axis at a distance smaller than d2, wherein d2 is smaller than d1′.

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.

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 spatially compact, lightweight positioning system for guiding an operator in positioning an ophthalmic instrument relative to an eye of a test subject has first and second light sources and an area detector spaced apart from a measurement axis of the instrument and from each other for providing positioning images which may be evaluated relative to stored calibration image information to determine current position of the instrument relative to the eye. The first and second light sources may fit within a lateral distance less than or equal to 25 mm. First and second illumination axes associated with the light sources may reside in a horizontal plane containing the measurement axis, and an observation axis of the area detector may reside in a vertical plane containing the measurement axis. The light sources and the area detector may be intersected by a plane which is normal to the measurement axis.

Systems, methods and apparatuses are provided for the measurement of intraocular pressure. These systems, methods and apparatuses can include an imaging apparatus for capturing two- or three-dimensional images or video of a patient's eye. An image reconstruction based on the captured images or video can be performed, and measurements can be taken of blood vessel features, curvature metrics, or distances between point pairs. In some embodiments, blood pressure measurements can also be taken synchronously with the captured images or video. From these measurements, a relationship between certain medical condition (e.g., elevated intraocular pressure, heart arrhythmia) and the extracted metrics can be established.