Abstract: A light section is generated on the object with an arrangement for the contactless section-like form measurement of curved surfaces by means of an optical detector functioning in a raster-like manner. The light section is received at an angle inclined to the viewing axis by an anamorphotic system and imaged onto a receiver.

Abstract: An optical apparatus for providing a two-dimensional output representation of reflection characteristics of an eye fundus in which a laser beam is passed through an anamorphic optical element to produce an output beam focused on a first axis and dispersed on a second axis normal to the first axis forming a line. The line of the output beam is directed onto a scanning element which moves the beam along the first axis and a focusing element directing the output beam from the scanning element through the pupil of the eye onto the fundus, the size of the beam being such that it has a small cross sectional area at the pupillary plane of the eye compared to the diameter of the pupil. The light from the fundus is reflected back through an exit aperture which is large compared to the cross sectional dimension of the input beam at the pupillary plane. The device includes a detector which extends along the non-scanning coordinate of the scanned area.

Abstract: A catadioptric optical imaging system comprises a dioptric assembly (20) and a catoptric assembly (21), which are positioned with respect to each other to form an imaging system of long focal length. The dioptric assembly (20) comprises two confocal paraboloidal mirrors (22, 23) arranged to form a telescope of the Mersenne type. The catoptric assembly (21) comprises lens elements arranged in two groups, viz., a field group (25) and a relay group (26), which are coaxially disposed with respect to the dioptric assembly (20). Only two different optical materials, viz., calcium fluoride crystal and Hoya LAC7 glass, are used in making the lens elements of the dioptric assembly (20). The dioptric assembly (20) is color-corrected at five wavelengths and has only negligible secondary and higher-order spectra in a wavelength band extending from the ultraviolet region to the near infrared region of the optical spectrum.

Abstract: An illuminating unit for a standard slit lamp is described, which can be mounted as a structural unit on the prism head of the standard slit lamp. The illuminating unit enables photographic documentation of the optical sections observed.

Abstract: An eyeglass/binocular combination wherein the binoculars are mounted on an eyeglass frame. The eyeglass lenses may be made of any material and may be of any thickness. The eyeglass frame has two separate lower openings for the eyeglass lenses and two separate upper openings for vision through the binoculars.

Abstract: A retrofocus-type objective for an endoscope which comprises a first lens component comprising a negative lens, a stop, a second lens component comprising a positive meniscus lens, a third lens component comprising a positive lens, a fourth lens component comprising a cemented doublet which consists of a positive lens and a negative lens, and a fifth lens component comprising positive lens, the retrofocus-type objective for an endoscope being arranged to be focused by advancing the third and fourth lens components.

Abstract: Disclosed is an ophthalmic instrument provided with an illuminating system for illuminating an eye being examined, an imaging system for imaging a predetermined portion of the eye being examined at a predetermined image plane position, and a detecting system for detecting any variation in the reflected light from the front-eye-part of the eye being examined by a nictitation of the eye being examined without depending on the quantity of illuminating light of the illuminating system.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: An eye refractometer is disclosed. It comprises a projection optical system including a light source portion and an objective lens disposed opposite to an eye under test, and a ring-shaped diaphragm or perforated mirror for forming a ring-shaped image pattern of the pupil of the eye and on the retina, a bundle of rays from the light source are projected to the eye under test through the objective lens and the diaphragm to form a ring-shaped pattern image at the retina of the eye under test through the peripheral area of a pupil surface of the eye under test; a light receiving optical system for receiving light reflected from the retina in a ring-shaped pattern image on a photo-electric detector through the central portion of the pupil; and a microprocessor for measuring the size and the configuration of the ring-shpaed pattern image from signals emitted from the photo-electric detector, and determining the refractivity of the eye under test therefrom.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: Photo plotter aperture members each have a beam forming trasnsparent ring and a central transparent cross in communication with the ring. The rings of the different members are of different diameters but of the same thickness as the lines of the respective crosses to provide uniform exposure during half diameter strokes of the aperture members.

Abstract: A simple pointspread retinoscope and method of retinoscopy is described. The retinoscope consists of a variable radius shield mounted on a light source, to provide variable eccentricity between the axis of the light source and the edge of the shield. The observer points the retinoscope light source at the eye of a subject, and observes the retinal reflex over the edge of the shield. If a crescent is observed, the shield is rotated to a larger radius location and the procedure repeated. The highest numbered radial step at which a crescent of light appears in the pupil provides the eccentricity of the light source, and from this value, the value of the radius of the pupil, and the value of the distance between the shield and the pupil the defocus of the subject eye can be determined.

Abstract: A zoom lens having a range of equivalent focal lengths (EFL) which extend from a dimension above the diagonal of the film plane of the lens to a telephoto focal length, where the lens comprises three groups of which two are movable to vary the EFL.

Abstract: Apparatus is disclosed for pre-determining laser coagulation dosages and for monitoring laser photocoagulation during treatment by detection of radiation produced in the eye. Embodiments of the present invention comprise means for applying radiation to a target in an eye (1, 2, 3, 5, 6, 7 and 9) and means for detecting the radiation produced by the target having wavelengths different from the wavelength of the applied radiation (4, 200, 12 and 13). In various embodiments, the radiation produced by the target is fluorescence radiation, Raman radiation, two photon excitation radiation and so forth.

Abstract: An eye fundus camera for taking photographs of a patient's eye fundus. The camera includes a pair of viewing targets located at the opposite sides of the optical axis. A switch is provided for alternately energizing the targets so that an appropriate one of the targets emits light beams when the camera housing is placed to take photographs of one of the patient's eyes.

Abstract: Swim goggles have a pair of eye pieces, each eye piece having a lens with an essentially rigid peripheral frame. Each eye piece has a seal assembly which includes a seal holder and a seal gasket. The seal holder is secured to the frame and has a pair of spaced flanges extending in a direction generally away from the respective lens. Space between the flanges of the seal holder provides a groove extending around the eye piece and the seal holder is resiliently deformable but relatively stiff. The seal gasket is fitted within the space between the flanges and has an outer face standing clear of the flanges to contact the wearer's face. The seal gasket is resiliently deformable and softer than the seal holder to provide a secure but comfortable seal with the wearer's face. Selection of the relative resiliences of the seal holder and seal gasket permits accommodation to a wide variety of faces and extends use of the goggles. A swim mask with single lens provided with a seal assembly as above is an alternative.

Abstract: A visual acuity testing apparatus is herein disclosed which comprises a test chart displayer having a display surface pointing to an upward direction; a first reflector, for downwardly reflecting a light beam from the test chart displayer, disposed above the displayer; and a second reflector for reflecting the light beam, reflected by the first reflector, towards eyes to be tested.Said test chart displayer and the first reflector for reflecting and propagating the light beam from the displayer are contained in a leg of a table and the second reflector for reflecting the light beam from the first reflector towards the eyes to be tested is supported by a supporting arm of the table.

Abstract: A zoom lens having at least three components, or, from front to rear, a first component of positive refractive power, a second component for variation of the image magnification, and a third component for image shift compensation, wherein said first lens component is constructed from a front group of lens elements l.sub.A of positive refractive power and a rear group of lens elements l.sub.B of negative refractive power, thereby letting f.sub.A and f.sub.B denote the focal lengths of said front and rear lens groups respectively, the following condition is satisfied:1.5f.sub.A <.vertline.f.sub.B .vertline.<4f.sub.Aand said rear lens group l.sub.B is made movable for focusing.

Abstract: A self-examination apparatus for the eye and the surrounding facial area is described in which a lens supported by housing can be moved with relation to the observer to provide a detailed or amplified image of the eye. The housing includes a substantially extended member for preventing sunlight from inadvertently being reflected off the lens into the observer's eye. The examination system further includes a self-illumination system that can provide the illumination when ambient conditions will not provide sufficient illumination for self-examination.

Abstract: An electrostatic display device of electrically variable reflectivity has a fixed electrode with an insulated face and a conductive resilient sheet. One portion of the sheet is held against the insulated face so that when a voltage is applied between the fixed and the variable electrodes, the free end of the variable electrode is drawn to the insulated fixed electrode. An ancillary extension of the variable electrode is sandwiched and compressed between an elastomeric pad and a metal terminal to provide reliable electrical contact to the delicate variable electrode. The terminal is preferably one of an elongated and acutely curved contacting surface such as the surface of a small wire contacting the variable electrode at right angles to the direction of flexure when activated by appliction of voltage. Alternatively the terminal may consist of a plurality of elongated and convexly curved contacting surfaces, i.e. a corduroy-like metal surface.