Abstract: A sensor 17 detects a quantity of light emitted by an alignment light source 21 and reflected by an eye. A comparison circuit 53 compares a quantity of the reflected alignment light with a predetermined quantity of reference light. If the reflected alignment light is less in quantity than the reference light, the comparison circuit 53 judges that there exist stains which exert a bad influence on the reflected alignment light. An operator obtains the judgment through a monitor 52 by which cautions are offered, so that the operator can operate an instrument in the best condition.

Abstract: An ophthalmological instrument has an anterior portion observation system for observing the anterior portion of an eye to be tested. The anterior portion observation system includes focus position shifting means capable of properly focusing in at least two different portions of the eye.

Abstract: A noncontact type tonometer has a nozzle for discharging fluid toward an eye to be tested, an alignment target projecting optical system for projecting an alignment target light used for aligning the eye and an apparatus body toward the center of curvature of the cornea of the eye from the axial direction of said nozzle while converging the same thereto by an objective lens and forming a virtual image at the center of curvature of the cornea, and an alignment light receiving optical system for reimaging the virtual image on a light receiving portion as a target image. The improvement is characterized in that the alignment light receiving optical system is provided with a light splitter adapted to split an alignment target light for forming the virtual image based on specular reflection of the cornea and guiding the same to the light receiving portion in order to verify the alignment with reference to coincidence or noncoincidence of the alignment target image.

Abstract: An ophthalmological instrument for the use of both corneal configuration and intraocular pressure measurement has alignment watching means for watching an alignment completion state upon receipt of an alignment completion signal which is output by alignment detecting means for detecting the alignment of an apparatus body with respect to an eye to be tested, corneal configuration measuring means for projecting a ring target mark onto the cornea of the eye and measuring a corneal configuration with reference to the ring target image, noncontact type intraocular pressure measuring means for discharging fluid toward the cornea in order to transfigure the cornea and measuring the intraocular pressure with reference to the amount of such transfiguration, and automatic executing means for executing the corneal configuration and intraocular pressure measurements in such a manner as that data of the ring target image is intaken in accordance with output of the alignment watching means in order to obtain data regarding

Abstract: A noncontact type tonometer has a nozzle for discharging a fluid toward an eye to be tested; an alignment target projecting optical system for projecting an alignment target ray of light in form of parallel pencil of rays toward the eye from the axial direction of the nozzle in order to verify the alignment between the eye and an apparatus body; an illuminating light source for emitting an illuminating light for illuminating the anterior portion of the eye; and an anterior portion observing optical system for observing the anterior portion through an objective lens. The anterior portion observing optical system is commonly used as an alignment target light receiving optical system.

Abstract: An alignment apparatus of a noncontact type tonometer has a target projecting system for projecting light emitted from a light emitting source to an eye to be tested along the axial line of a fluid discharging nozzle for discharging fluid and forming a target image on the eye, and an alignment light receiving optical system for receiving the target image along the axial line of the nozzle and forming an image of the target image on a light receiving sensor. The alignment apparatus of a noncontact type tonometer is characterized in that the light emitting source comprises a first and a second light emitting sources, the light receiving sensor comprises an area sensor, and the apparatus further has a control unit adapted to detect the positions of the target images of the first and second light emitting sources formed on the area sensor and to output an alignment completion signal when such detected positions are within a preset range on the area sensor.

Abstract: A noncontact type tonometer, in which an axial line extending in the direction of air pulse projected by an air pulse projecting nozzle towards a cornea of an eye to be tested is coaxial with an optical axis of an alignment optical system for verifying an alignment with respect to a vertex of the cornea, includes an anterior portion observing system capable of optically observing an anterior portion of the eye and having an optical axis coaxial at least with a part of the optical axis of the alignment optical system.

Abstract: A non-contact type tonometer is disclosed. It includes a fluid discharging device for discharging a fluid from a nozzle towards an eye to be tested and transfiguring the eye, an eye pressure measuring device for measuring the eye pressure of the eye based on the pressure of the fluid, and an alignment detecting device for detecting the aligning state of the nozzle of the fluid discharging device. It further includes an eye pressure value correcting device for correcting an actually measured eye pressure value obtained by the eye pressure measuring device based on an alignment error information of the nozzle with respect to the eye using the alignment detecting device.