Abstract: An optical prism mounting system is described that includes a prism having a flexible insertion tab system. Also described, is a prism holder having an insertion channel, and a method of mounting the prism in a tonometer. The flexible insertion tab system includes a spring tab and a bendable tab; the spring tab is flexed as the prism moves along the channel; the flexible insertion tab system connects with the prism holder and snaps into a locked position at the end of the channel; and the prism and the prism holder can be separated after use by disengaging the flexible insertion tab system. An optical operating range of the optical prism is from about 0 ADC to about 600 ADC, and the maximum time for setting the tonometer is not more than about 150 seconds.

Abstract: An optical prism mounting system is described that includes a prism having a flexible insertion tab system. Also described, is a prism holder having an insertion channel, and a method of mounting the prism in a tonometer. The flexible insertion tab system includes a spring tab and a bendable tab; the spring tab is flexed as the prism moves along the channel; the flexible insertion tab system connects with the prism holder and snaps into a locked position at the end of the channel; and the prism and the prism holder can be separated after use by disengaging the flexible insertion tab system. An optical operating range of the optical prism is from about 0 ADC to about 600 ADC, and the maximum time for setting the tonometer is not more than about 150 seconds.

Abstract: An iris dilator has a head spring transmitting a spring bias to a pair of limbs extending from the head spring. The limbs are provided with loops that can engage an inner perimeter of an iris while the bias exerted by the head spring results in a dilation occurring approximately at the four corners of an iris opening.

Abstract: A cataract emulsifying tool having a hollow shaft delivering pulsed fluid is improved by having a bend in the hollow tube or an angularly adjustable socket receiving the hollow tube. This disposes the axes of the handle and the hollow shaft at angles to each other to facilitate working over a prominent superior orbital rim or right and left angles ergonomically benefiting a surgeon.

Abstract: An applanation tonometer uses an active pixel sensor array to accurately detect total illumination in a region surrounding an applanated area so that a microprocessor can determine the applanated area based on an inversion of the illumination received by the sensor.

Abstract: A microprocessor-controlled tonometer measures both systole and diastole occurring in intraocular pressure so that this information can be used to estimate perfusion pressure. The microprocessor determines a ratio between ocular pulse amplitude and mean intraocular pressure, derives a multiplier from the ratio, multiplies the mean intraocular pressure by the multiplier to estimate mean central retinal artery pressure, and then estimates perfusion pressure by subtracting mean intraocular pressure from the estimate of central retinal artery pressure.

Abstract: A tonometer uses ambient light available in an eye examining room, rather than a dedicated source of light, to examine a characteristic of an eye. A digital camera in the tonometer views an image of the eye as it is engaged by a contactor that applanates or indents the cornea. An electromagnetic mount for the contactor can supply a force pressing the contactor against the eye. While the examiner observes the resulting image a strain gauge can also measure the deformation pressure applied to the eye by the contactor. A microprocessor can then determine a characteristic of the eye from signals supplied by the camera and the strain gauge or the electromagnet force applier.

Abstract: A replaceable cornea contactor for an eye examining instrument is made to be discarded after each use. A bendable tab molded on the cornea contactor is deformed by a strain gauge as the cornea contactor is inserted into a cornea contactor holder, and a signal from the strain gauge is used to verify that a previously unused cornea contactor has been inserted into the holder. A microprocessor is programmed to recognize the signal produced by initial deformation of the cornea contactor tab so as to proceed with an eye examination only after receiving the strain gauge signal verifying that a previously unused cornea contactor has been inserted.

Abstract: An applanation tonometer and its operation involve an actuator pressing a prism with a variable and determinable force against a cornea of an eye while a source directs light to reflect from an applanation surface of the prism to a detector producing a detected light signal received by a microprocessor. Such a tonometer produces a diastolic phase signal and a systolic phase signal representing the complete intra ocular pressure experience of the eye being examined. The signal information allows combined diastolic and systolic IOP to be determined in several corroborating ways and also yields measures of ocular blood flow and tonography.

Abstract: A replaceable applanation prism for an eye examining instrument is made to be discarded after each use. A bendable tab molded on the prism is deformed by a strain gauge as the prism is inserted into a prism holder, and a signal from the strain gauge is used to verify that a previously unused prism has been inserted into the holder. A microprocessor is programmed to recognize the signal produced by initial deformation of the prism tab so as to proceed with an eye examination only after receiving the strain gauge signal verifying that a previously unused prism has been inserted.

Abstract: An applanation tonometer with a replaceable prism for contacting a cornea has emitter and detector ports arranged opposite each other on opposite sides of a longitudinal axis, with the ports aimed at about 45° to the longitudinal axis. Light from an emitter confronting one of the ports is incident on the applanation surface at about 45° so that light reflecting internally of the prism from the applanation surface is directed toward the opposite port for detection. The portion of the light internally reflected from the applanation surface provides a signal indicating the size of the applanated area, from which intraocular pressure is determined.