Abstract: An apparatus for examining the ocular fundus of an eye, in which an illuminating device is provided with non-overlapping apertures positioned substantially side by side, and in which an image of the apertures is formed on a part of the ocular fundus; an image of the illuminated ocular fundus is formed in a detecting plane in response to reflection from this fundus in such a manner as to provide a stereo pair of images of the ocular fundus in the detecting plane which are detected and then electronically processed and digitally analyzed thereby to display information about the ocular fundus under examination; the pupil position is also detected and the eye is then automatically aligned relative to the optical axis of the image, at least part of which is common to the axis of the illuminating device.

Abstract: A lensmeter is disclosed for determining the refractive properties of a test lens, including an optical system to produce an ellipse of light at a detecting plane having information of such properties, a scanning linear photodiode array at the detecting plane for producing video output signals, a first integrator to integrate the video output signal from each photodiode, a compensator to compensate each video output signal for the light sensitivity of each photodiode, a second integrator to integrate the compensated video signals over the range of the distribution of light of an area of the ellipse being scanned, a circuit, connected to the second integrator, to detect the median point of the distribution, and a microprocessor to provide data identifying the median point in response to the detection.

Abstract: An automatic lensmeter (48) for determining the refractive properties of a test lens (76) including optics (52, 58, 62, 64, 68, 70, 72, 74) for producing a collimated, nonrotational beam of light, equally disposed about and propagating along an optical axis (50), which is refracted by the test lens (76), a nonrotational mask (18) having an annulus (24) for generating a stationary elliptical loop (28) of light at a detecting plane (26), the loop (28) having a shape, size and location dependent on the refractive properties of the test lens (76), and a photodetector (31) at the plane (26) to intercept the loop 28. The lensmeter (48) has no moving optical components and, due to the loop 28, provides an infinite number of points to determine very accurately one or more of the refractive properties, thereby overcoming problems with prior automatic lensmeters having relatively rotational optics and/or providing a finite number of points at a detecting plane.