Abstract: A process and apparatus for dynamic or static perimetry of the human eye wherein topographical measuring threshold values of eye sensitivity for the eye being tested are obtained and are electronically compared with stored standard values of eye sensitivity corresponding to the testing conditions. An indication is provided of deviations between the measured values and the stored standard values. The apparatus includes a perimetry device, a computer for storing the standard values and at least one program for controlling the perimetry device and for comparing the measured values with the stored standard values and a display arrangement for displaying the values and deviations.

Abstract: A photographic lens system is constituted of four lens components and four lens elements, comprising a first lens component of a meniscus positive lens with its convex surface on the object side, a second lens component of a biconcave lens, a third lens component of a biconvex lens and a fourth lens component of a meniscus negative lens with its convex on the image side. It is so arranged that the shortening of the focal length in such a manner that the image quality is kept good over a wide angle of field of view and the reducing of the telephoto ratio are well balanced so as to enable provision of a very compact photographic lens system having superior characteristics.

Abstract: An eye fundus camera illuminates the eye to be inspected with a light that does not cause dilation or contraction of the eye pupil. In the camera, a photographic system forms an image of the eye fundus on a recording body. A projection system projects an image, of infrared light, or predetermined shape on the eye fundus. An observation system observes the image. Focusing means permit focusing the eye fundus image on the recording body at the same time as the image of the mark is formed on the eye fundus. The system is focused by operating the focusing means to focus an image of the mark.

Abstract: A rear viewer for automobile is disclosed having means for mounting an optical system on an automobile rear window glass, which means consists of a box member made of synthetic resin or light metal and holds the optical system made of synthetic resin and composed of optical elements selected from a group of one or more Fresnel concave lenses of plate shape, plate-like prisms, with or without a plate-like mirror. Light beams from an optical field at the immediate outside of an automobile rear end portion are converged and refracted so as to enable an automobile driver to see the conditions of the aforesaid optical field, whereby the safety in automobile driving is improved. An auxiliary optical means consisting of a combination of the aforesaid plate-shaped optical elements and mounted at the rear end portion of the automobile may be used in conjunction with the optical system of the box member, for further improving the driver's view of the aforesaid optical field.

Abstract: A photographic lens system such as a telescopic lens system adapted for use with a rear stop diaphragm in which the backfocus is about 0.3F, the F number is about F/2.8, the system is small in size and aberrations are well compensated for. Front and rear lens groups are provided with the front group including in order from the object positive, negative, positive and positive lenses while the rear group includes negative and positive lenses. Preferred focal lengths, radii of curvature, refractive indices, and Abbe numbers for each of the lenses are disclosed.

Abstract: An optical objective, usable for reproduction as well as for photographic and cinematographic purposes, consists of five components--two on the object side and three on the image side of a diaphragm space--constituted by a total of seven meniscus-shaped lenses all of whose surfaces are concave toward the diaphragm space, the first object-side component and the middle image-side component being negatively refracting doublets. The objective is bodily movable for focusing purposes and its two object-side components are correlatedly axially shiftable to minimize aberrations over a wide range of magnification ratios.

Abstract: An optical system for forming an image of the retina of an eye which is to be examined. The optical system has two groups of lenses which cooperate to form the image. The first lens group is in contact with the cornea of the eye of the patient via the eye liquid or a physiological saline solution. The second lens group is separated from the first group by an air space, and may serve to conjugate the pupil of the patient with the pupil of the doctor or other observer. If desired, the lenses of the first group may have a central opening which receives a light pipe for illuminating the eye of the patient. Also, if desired, the lenses of the second group may include either spherical or aspherical lenses, or a combination of both, or may include one or more Fresnel lenses.

Abstract: A constant-speed scanning lens system comprising a first, second, third, fourth and fifth lens components, the first lens component being a positive meniscus lens arranged concave toward the incident side, the second lens component being a negative lens, the third, fourth and fifth lens components being positive meniscus lenses respectively arranged concave toward the incident side, the constant-speed scanning lens system having a small F number, wide field angle and compact size.

Abstract: Apparatus herein disclosed comprises a photographing system having an optical system of variable magnification and an illumination system having a light source for photographing and a light source for observing. In the apparatus, the existing photographing magnification of the optical system is detected and the quantity of light incident upon a film or a finder visual field is controlled depending upon the detected magnification so as to obtain an optimum exposure to the film of the photographing system or to maintain the brightness of the visual field constant. To attain the control of quantity of light, light passing through the illumination system or light passing through the optical system is gradually reduced with widening of the angle of field. Alternatively, intensity of light emitted from the light source for observing or light emitting time of the light source for photographing is altered depending upon the detected magnification.

Abstract: A wide-angle indirect ophthalmoscope that enables an operator to view the retina from the posterior pole to the equator as a single image. The ophthalmoscope has an observable field that can include the entire retina. The ophthalmoscope includes optical fibers built into a contact lens in a circular pattern. The fibers are connected to a light source to illuminate the retina, and the contact lens is utilized for observation. The fibers are maintained in a pre-determined fixed orientation in the lens to produce uniform illumination over the entire retina.

Abstract: A lens system for facsimile comprising a first positive lens component, a second biconcave lens component and a third lens component consisting of a negative lens element and a positive lens element, said lens system having high OTF and assuring very low distortion as well as high intensity for marginal rays.

Abstract: A deflector, through which a subject views a target or visual stimulus, can independently move the visual stimulus horizontally and vertically to stimulate or compensate the subject's eye movement and can alter the optical distance to stimulate or compensate accommodation (focus). The target is projected on the subject's eye by way of two mirrors serially disposed in the projecting path and mounted for rotation about vertical and horizontal axes, respectively. Lens elements produce an undistorted unity magnification image of the eye at each mirror, with the center or rotation of the eye in each image nominally on the axis of rotation of the respective mirrors, and servo motors independently rotate the mirrors about their respective axes to produce vertical and/or horizontal deflection of the stimulus at the eye.

Abstract: A compact retrofocus type lens system having a first lens component of a positive meniscus lens with its convex surface facing the object side, second and third lens components of negative meniscus lenses with their convex surfaces both facing the object side, a fourth lens component of a positive meniscus lens with its convex surface facing the object side, a fifth lens component of a biconvex lens, a sixth lens component of a biconcave lens, a seventh lens component of a positive meniscus lens with its convex surface facing the image side and an eighth lens component of a positive meniscus lens with its convex surface facing the image side. This lens system is so arranged that the lateral chromatic aberration is made small by increasing the Abbe number of the first lens component and also that the Petzval sum which is deteriorated thereby is corrected by increasing the refractive index of the fourth lens component.

Abstract: An objective of the pancratic type includes a varifocal front lens group and a fixed-focus rear lens group, the latter consisting of five air-spaced singlets. The front lens group is constituted by a positive first component consisting of three singlets, an axially shiftable negative second component consisting of a singlet and a doublet, and an axially shiftable positive third component in the form of a nearly planoconvex singlet of low power.

Abstract: A six member microscope objective having a numerical aperture of substantially 0.90 and a magnification of substantially 100x for use without oil is disclosed.

Abstract: A Goldmann-type perimeter is provided which automatically performs kinetic perimetry without the need for manual intervention.

Abstract: A reproducing objective for video disks comprising a first, second and third lenses in which the first lens is a biconvex lens, the second lens is a negative meniscus lens, and the third lens is a positive meniscus lens, the reproducing objective for video disks being compact in size and light in weight and having a long working distance.

Abstract: A retrofocus lens subtending a field angle up to 84.degree. or more characterized by compactness, fast relative aperture, and good aberration correction. These characteristics are obtained by selection of the relative powers of a front negative and a rear positive group, and the dispersion of the front elements.

Abstract: A telephoto objective comprising a stationary convergent front lens group and a rear lens group which includes a lens member axially movable for focusing behind a front lens member which remains stationary during focusing, and an operating mechanism therefor. In order to achieve excellent stability of the various aberrations and particularly spherical aberration throughout the focusing range, compensation for the residual aberrations introduced by the front lens group is concentrated in the stationary front member of the rear lens group, while the movable rear member is configured to provide minimized variation of aberrations by constructing these two members as being divergent with their front surfaces convex to the object. In this particular arrangement, the movable member is moved toward the image plane as the objective is focused from the position for an object at infinity to the position for a close object.

Abstract: This invention is directed to a telephoto lens. The telephoto lens comprises a positive front lens group which remains stationary during focusing and a negative rear lens group having a stationary sub-group and at least one movable sub-group. The movable sub-group has a positive refracting power with its front surface being convex toward the object. The stationary sub-group has a negative refracting power with its rear surface being concave toward the image. The movable sub-group is moved on the optical axis toward an object so as to cause said telephoto lens to focus an object at near distance from its focusing on an object at far distance.