Abstract: A perimeter for perimetric eye testing is provided with an electronic control mechanism for varying the brightness of the light signals in a preselected manner such that reproducibility of the examination can be achieved. An optical indicating arrangement is included to indicate the brightness values to the examiner, while the electronic control mechanism can further control an electronic recorder for recording the results of the examination.

Abstract: A laser interference instrument for determination of the visual acuity of the human eye includes an interference optical system for producing an interference light pattern mounted on a slit lamp microscope disposed on an instrument support that is finely adjustable horizontally and in height. The interference optical system includes a laser light source and a rotatable turntable carrying a plurality of plane parallel plates or wedge plates which may be selectively moved into the light path of the laser light source to produce different interference patterns to be projected onto the human eye and which are then observable through the slit lamp microscope.

Abstract: A perimetric eye examination device is provided having light-emitting diodes for the respective light sources which are perceived during the eye examinations. These light-emitting diodes are controllable for their brightness, either in linear dependence on the current, or in linear dependence on the pulse width repetition ratio of current pulses supplied to the light-emitting diode. The brightness perceived from the respective light-emitting diodes on the surface of the perimetric eye examination device also may be varied in accordance with physiological characteristics of the eye wherein the light-emitting diodes are distributed on the surface of the device with the brightness increasing from the central area of the observation area toward the periphery of the observation area.

Abstract: An exchangeable device providing test patterns for eye examinations is provided to be insertable into an eye examination instrument, such as a projector or an eyepiece instrument. This device includes a cassette containing a rotatable disk carrying different test patterns with the test patterns being visible through light transparent portions of the cassette. The cassette is insertable into the instrument, and the test pattern is illuminated through the light transparent portions with the disk being rotated through coupling elements connected to a drive mechanism of the instrument to vary the test pattern.

Abstract: A perimetric testing apparatus is described for use in testing the field of vision of human eyes. This apparatus includes an approximately hemispherical shell together with a device for projecting successive light pattern groups onto the inner surface of the shell. The device includes shadow masks, representative of different light pattern groups, which may be selectively inserted into the light path of a light source projector. The apparatus may be used in a dynamic perimeter.

Abstract: The color vision of a subject to be tested is evaluated by the presentation of a series of test panels having different colors to the subject. Each pair of test panels has prescribed maximum emission values over established wavelength ranges and wavelength values. Depending upon the ability to discern colors of the subject to be tested, the respective pairs of test panels will appear to the subject to have different degrees of color and intensity, so that it can be determined whether or not the color vision of the subject being tested is normal or is protanopic deuteranopic and the degree of the latter color deficiencies can also be evaluated.