Abstract: An electrically conductive GaAs crystal has an atomic concentration of Si more than 1×1017 cm?3, wherein density of precipitates having sizes of at least 30 nm contained in the crystal is at most 400 cm?2. In this case, it is preferable that the conductive GaAs crystal has a dislocation density of at most 2×10?2 cm2 or at least 1×10?3 cm2.

Abstract: An ophthalmologic apparatus includes a visual target projection system that is configured to present a visual target to a subject eye at a predetermined examination distance under a presentation condition according to the examination distance, and a controller that is configured to control the visual target projection system. The controller is configured to control the visual target projection system to present the visual target at a first examination distance for a far-point examination of the subject eye, a second examination distance for a near-point examination of the subject eye, and at least one third examination distance different from the first examination distance and the second examination distance.

Abstract: In an ophthalmic examination system of one embodiment, an internal examiner terminal is used by an internal examiner in a facility where an ophthalmic examination apparatus is installed. An external examiner terminal is used by an external examiner outside the facility. A management apparatus includes a communication establishment unit, and an information transfer unit. The communication establishment unit is capable of establishing communication between at least two apparatuses selected from the ophthalmic examination apparatus, the internal examiner terminal, and the external examiner terminal. The information transfer unit is configured to transfer information sent from one of the at least two apparatuses whose communication has been established by the communication establishment unit. Each of the ophthalmic examination apparatus, the internal examiner terminal, and the external examiner terminal includes an output unit configured to output information transferred by the information transfer unit.

Abstract: According to one embodiment, an ophthalmologic apparatus includes an optical system, a support, a drive unit, an alignment optical system, two or more imaging units, an analyzer, and a controller. The optical system acquires data of an eye. The support is configured to support the face of a subject. The drive unit moves the optical system and the support relative to each other. The alignment optical system projects an indicator for performing alignment of the optical system with respect to the eye onto the anterior segment of the eye. The imaging units photograph the anterior segment of the eye, onto which the indicator is being projected, substantially simultaneously from different directions. The analyzer analyzes two or more photography images captured substantially simultaneously by the imaging units to specify the position of the eye. The controller controls the drive unit based on the position specified by the analyzer.

Abstract: According to one embodiment, an ophthalmologic apparatus includes an optical system, a support, a drive unit, an alignment optical system, two or more imaging units, an analyzer, and a controller. The optical system acquires data of an eye. The support is configured to support the face of a subject. The drive unit moves the optical system and the support relative to each other. The alignment optical system projects an indicator for performing alignment of the optical system with respect to the eye onto the anterior segment of the eye. The imaging units photograph the anterior segment of the eye, onto which the indicator is being projected, substantially simultaneously from different directions. The analyzer analyzes two or more photography images captured substantially simultaneously by the imaging units to specify the position of the eye. The controller controls the drive unit based on the position specified by the analyzer.

Abstract: An ophthalmic examination system of an exemplary embodiment includes a plurality of ophthalmic examination apparatuses, a plurality of examiner terminals, a communication establishing device, an information transmitting device, and an output device. The communication establishing device is capable of establishing communication between at least three apparatuses including at least one of the plurality of ophthalmic examination apparatuses and at least two of the plurality of examiner terminals. The information transmitting device transmits at least part of information transmitted from one of the at least three apparatuses between which the communication has been established by the communication establishing device, to at least one of other two or more apparatuses. The output device outputs information transmitted by the information transmitting device.

Abstract: According to an ophthalmic examination system of an embodiment, a user interface of an examination instruction apparatus is used to enter an instruction for examination. A first communication unit sends the instruction to an ophthalmic examination apparatus in real time. An examination optical system of the ophthalmic examination apparatus includes an optical element applied to an eye and a projection system that projects an examination light beam onto the eye through the optical element. An information presentation optical system includes a display and a light guide system that guides a display light beam from the display to the eye through the optical element. A second communication unit receives the instruction from the examination instruction apparatus. A controller displays the instruction received by the second communication unit on the display in real time.

Abstract: According to one embodiment, an ophthalmologic apparatus is configured such that an operation unit is attached thereto. The ophthalmologic apparatus includes a measuring head, a user interface, and a controller. The measuring head is configured to perform optical measurement of a subject's eye. The user interface is used for performing an operation in relation to the optical measurement of the subject's eye. The controller is configured to detect whether an operation on the operation unit is enabled. Further, the controller is configured to perform at least display control for the user interface in different operation modes between an enabled state in which the operation on the operation unit is enabled and a disabled state in which the operation on the operation unit is disabled.

Abstract: An optotype presenting apparatus that is capable of carrying out examinations accurately is provided. An optotype presenting apparatus includes a display and a controller. The display includes left eye optotype display regions and right eye optotype display regions. The left eye optotype display regions output light having a first polarization axis. The right eye optotype display regions output light having a second polarization axis orthogonal to the first polarization axis. The left eye optotype display regions and the right eye optotype display regions are alternately arranged along pixel lines. The controller is capable of displaying a plurality of optotypes selectively on the display. Further, the controller controls the display based on a type of an optotype displayed on the display to change display luminance.

Abstract: According to one embodiment, an optometric apparatus includes a movement mechanism system and left and right optometry units. The movement mechanism system is suspended from an arm. The left and right optometry units are configured to be moved by the movement mechanism system. The left and right optometry units each include an optical element applying part, a target presenting part, and an objective measurement part. The optical element applying part is configured to selectively apply a plurality of optical elements to a subject's eye. The target presenting part is configured to selectively present a plurality of visual targets to the subject's eye. The objective measurement part is configured for performing objective refraction measurement of the subject's eye.

Abstract: In an ophthalmic examination system of one embodiment, an internal examiner terminal is used by an internal examiner in a facility where an ophthalmic examination apparatus is installed. An external examiner terminal is used by an external examiner outside the facility. A management apparatus includes a communication establishment unit, and an information transfer unit. The communication establishment unit is capable of establishing communication between at least two apparatuses selected from the ophthalmic examination apparatus, the internal examiner terminal, and the external examiner terminal. The information transfer unit is configured to transfer information sent from one of the at least two apparatuses whose communication has been established by the communication establishment unit. Each of the ophthalmic examination apparatus, the internal examiner terminal, and the external examiner terminal includes an output unit configured to output information transferred by the information transfer unit.

Abstract: According to an ophthalmic examination system of an embodiment, a user interface of an examination instruction apparatus is used to enter an instruction for examination. A first communication unit sends the instruction to an ophthalmic examination apparatus in real time. An examination optical system of the ophthalmic examination apparatus includes an optical element applied to an eye and a projection system that projects an examination light beam onto the eye through the optical element. An information presentation optical system includes a display and a light guide system that guides a display light beam from the display to the eye through the optical element. A second communication unit receives the instruction from the examination instruction apparatus. A controller displays the instruction received by the second communication unit on the display in real time.

Abstract: According to one embodiment, an ophthalmologic apparatus includes an optical system, a support, a drive unit, an alignment optical system, two or more imaging units, an analyzer, and a controller. The optical system acquires data of an eye. The support is configured to support the face of a subject. The drive unit moves the optical system and the support relative to each other. The alignment optical system projects an indicator for performing alignment of the optical system with respect to the eye onto the anterior segment of the eye. The imaging units photograph the anterior segment of the eye, onto which the indicator is being projected, substantially simultaneously from different directions. The analyzer analyzes two or more photography images captured substantially simultaneously by the imaging units to specify the position of the eye. The controller controls the drive unit based on the position specified by the analyzer.

Abstract: According to one embodiment, an optometric apparatus includes a movement mechanism system and left and right optometry units. The movement mechanism system is suspended from an arm. The left and right optometry units are configured to be moved by the movement mechanism system. The left and right optometry units each include an optical element applying part, a target presenting part, and an objective measurement part. The optical element applying part is configured to selectively apply a plurality of optical elements to a subject's eye. The target presenting part is configured to selectively present a plurality of visual targets to the subject's eye. The objective measurement part is configured for performing objective refraction measurement of the subject's eye.

Abstract: According to one embodiment, an ophthalmologic apparatus is configured such that an operation unit is attached thereto. The ophthalmologic apparatus includes a measuring head, a user interface, and a controller. The measuring head is configured to perform optical measurement of a subject's eye. The user interface is used for performing an operation in relation to the optical measurement of the subject's eye. The controller is configured to detect whether an operation on the operation unit is enabled. Further, the controller is configured to perform at least display control for the user interface in different operation modes between an enabled state in which the operation on the operation unit is enabled and a disabled state in which the operation on the operation unit is disabled.

Abstract: A subjective optomater that is capable of measuring accommodation ability of an eye while reducing the influence of accommodative convergence is provided. A subjective optometer includes: a visual target that is presented to an eye through a measuring optical axis; a measuring optical system that includes a spherical lens capable of changing spherical power on the measuring optical axis; a spherical power changer that changes the spherical power of the spherical lens; and an optical axis deflector that deflects the measuring optical axis so as to align the measuring optical axis with a visual axis of the eye, wherein accommodation ability is measured based on the spherical power of the spherical lens in a state in which the measuring optical axis is deflected by the optical axis deflector.

Abstract: A subjective optometer includes a visual target, deflectors, calculator and positioning parts. The visual target is presented a first distance away from eyes. The deflectors deflect first optical paths formed between the eyes and the visual target to form second optical paths causing the eyes to observe the visual target as if the visual target is presented at a second distance shorter than the first distance. The calculator calculates accommodation stimulus amount for causing the eyes to observe the visual target as if presented at the second distance based on convergence accommodation amount of the eyes caused by the second optical paths, the first distance and the second distance. The positioning parts include spherical lenses and position spherical lenses having spherical powers corresponding to the accommodation stimulus amount in the second optical paths. The eyes are examined with the spherical lenses positioned in the second optical paths.

Abstract: An optotype presenting apparatus that is capable of carrying out examinations accurately is provided. An optotype presenting apparatus includes a display and a controller. The display includes left eye optotype display regions and right eye optotype display regions. The left eye optotype display regions output light having a first polarization axis. The right eye optotype display regions output light having a second polarization axis orthogonal to the first polarization axis. The left eye optotype display regions and the right eye optotype display regions are alternately arranged along pixel lines. The controller is capable of displaying a plurality of optotypes selectively on the display. Further, the controller controls the display based on a type of an optotype displayed on the display to change display luminance.

Abstract: A subjective optomater that is capable of measuring accommodation ability of an eye while reducing the influence of accommodative convergence is provided. A subjective optometer includes: a visual target that is presented to an eye through a measuring optical axis; a measuring optical system that includes a spherical lens capable of changing spherical power on the measuring optical axis; a spherical power changer that changes the spherical power of the spherical lens; and an optical axis deflector that deflects the measuring optical axis so as to align the measuring optical axis with a visual axis of the eye, wherein accommodation ability is measured based on the spherical power of the spherical lens in a state in which the measuring optical axis is deflected by the optical axis deflector.

Abstract: A visual acuity testing apparatus includes a target presenting unit for displaying various targets to be presented to a subject's eye, an optical element arranging device for retaining various optical elements, and selectively arranging the optical element corresponding to a response from the subject between the subject's eye and the target presenting unit, an operation section which is operated for selecting each of targets and each of the optical elements, a display section for displaying an operation image illustrating an operation content of the operation section, a memory for storing a plurality of target data illustrating each of the targets and operation image data illustrating the operation image, an arithmetic control section for extracting the target data and the operation image data from the memory according to an operation of the operation section, and an image output section having at least two output ports.