Abstract: A protective eyewear including a brow member, two temple arm members, a front lens and two side shields. The front lens is removably attached to the brow member within a channel formed therein. The lens includes a series of projections adjacent one edge thereof and the brow member including a corresponding series of slots opening into the channel. The projections on the lens are engaged within the slots in the brow member to lock the lens within the brow channel. The side shields are attached to the corresponding temple arm members by means of at least one projecting hub which is engaged within the temple arm. The nub preferably includes a central opening. The temple arm is molded to the side shield such that the temple arm material fills the central opening and engages the hub to lock the side shield in position. The eyewear provides a removable lens and also forms a protective structure that meets the eyewear impact resistance standards.

Abstract: This specification discloses a method of making a hologram imaged substantially without aberrations during the use when the wavelength of a light during the making differs from the wavelength of a light during the use and having high diffraction efficiency. In order to eliminate any aberration occuring when the hologram is used in a light beam of a different wavelength and to obtain high diffraction efficiency, a making light beam is caused to enter a predetermined coaxial optical system from outside the axis thereof to impart a suitable aberration, and a hologram is formed on a hologram sensitive material by the making light beam.

Abstract: In a zoom lens of two-unit construction comprising a first lens unit having negative refractive power as a whole and a second lens unit having positive refractive power as a whole, the first lens unit comprises, in succession from the object side, a negative lens having its concave surface of sharp curvature facing the image side and a positive lens having its convex surface facing the object side, the second lens unit has, in succession from the object side, at least a positive lens, a positive lens, a negative lens having its concave surface of sharp curvature facing the image side, and a positive lens having its convex surface of sharp curvature facing the image side, the first lens unit has at least one aspherical surface, and the zoom lens satisfies the condition that 0.65<.vertline.f.sub.1 /(f.sub.w .multidot.f.sub.T).sup.1/2 .vertline..ltoreq.1.1.

Abstract: Ophthalmologic apparatus includes a light source for obliquely directing light beams into an eye to be examined to illuminate a region of interest therein, a lens system for viewing the region of interest, an optical magnifier assembly for magnifying the viewed region of interest, and an image intensifier for intensifying the image of the viewed region of interest. The light source directs light into the eye from opposite sides thereof to intersect in the plane of the region of interest in the eye.

Abstract: Foldable glasses and a container combination in which the lense frames of the glasses are hinged at the bridge where they are joined for folding back parallel to each other; retractable temples are provided which are hinged to the opposite sides of the lense frames from their bridge connections, with the temples also being foldable against the lense frames to produce a minimum sized article which fits in a rigid two part container defining a cavity of an overall shape and size to receive and protect the glasses when folded.

Abstract: A clamp assembly comprises a clamp (12) having two levers (1, 2) linked at middle areas thereof with first ends thereof closing together to form clamping jaws (5, 6) and second, opposite, ends thereof formed as opening grips (3, 4) for separating the clamping jaws, which are spring loaded toward one another. The clamping jaws (5, 6) have forked shapes. The branches of the forks, and the ends thereof, are arranged to be spaced from one another so that they extend across, or extend over, a bridge of a pair of eyeglasses to be placed on inner, upper edges of spectacle glasses (13) or on an eyeglass frame (14). A first lever (2) of the clamp (12) has thereon a clamp coupling element (10, 19, 22, 24) for being selectively attached to, and selectively detached from, an optical-device coupling element (18, 20, 23, 25) on an optical device. The clamp assembly makes possible an easy and quick exchange of optical devices to be attached thereto.

Abstract: This invention relates to an eye fundus photographing apparatus for photographing the fundus of an eye to be examined. The eye fundus photographing apparatus has an optical system for illuminating the fundus of the eye to be examined and also causing the illuminated fundus of the eye to be examined to be photographed at different photographing magnifications. Also provided is an operating mechanism for changing the photographing magnification. The photographing magnification is changed by the operating mechanism being operated in a predetermined manner. In addition, an interlocking device is provided for varying a portion of the optical system without changing the photographing magnification, by the operation of the operating mechanism succeeding to the operation of the operating mechanism for changing the photographing magnification by the optical system.

Abstract: Design forms are disclosed for wide-field infrared imaging systems characterized by a large ratio of entrance aperture to focal length, where the limiting aperture stop is located in the converging image space.

Abstract: An optometric apparatus includes an operating table and a vision test chart displaying device provided internally within the operating table. An optical group, including a plurality of reflection-type optical elements, are disposed within the operating table. The optical group repeatedly reflects an optical image of the vision test chart projected from the vision test chart displaying device along an optical path within said operating table. A first deflecting optical element reflects the optical image of the vision test chart reflected by the reflection-type optical element group outside the operating table in a first direction. A second deflecting optical element then reflects the optical image of the vision test chart reflected by the first deflecting optical element in a second direction toward the examinee's eyes.

Abstract: A new type of holographic recording in photorefractive crystals is disclosed, termed orthogonal data storage, in which counterpropagating, reflection mode holograms are wavelength multiplexed to form gratings lying along a common axis. It is shown that this configuration provides substantial improvements in data storage capacity in comparison to prior art systems and that higher coupling coefficients are achieved. In consequence, not only storage of data but a wide range of other devices including wavelength selective filters, lenses and optical correlation systems are disclosed. Further, methods of writing and processing metastable images are disclosed which substantially improve the strength of the gratings that are permanently developed in the medium. These methods include advantageous use of electrical potentials and photovoltaic properties, together with different interrelationships during processing.

Abstract: The invention provides a tinted pair of lenses for overcoming the deleterious effects of nystagmic oscillations, particularly in persons suffering from dyslexia, the tinting varying along the lateral direction and extending in each lens over at least two zones, a lighter tint being used in a first zone extending from the lens edge nearest to the nose of the wearer, when the lens is in use, to a position corresponding to the centre of the pupil, and a darker tint being used in a second zone extending over the remaining lens area.

Abstract: A pair of eyeglasses is disclosed in which at least a portion of the frame is made with a bore along its length. The bore can be filled with a colored material in order to change the appearance of the eyeglasses. Colored pipe cleaners are suitable for use as the colored material.

Abstract: A test card for use in eye examinations emulates the light return profile of a video display screen such as those commonly used in connection with computers. The test card is used for prescribing corrective lenses for a computer user. The test card is formed on an opaque planar medium and has a plurality of characters formed thereon for reading by the patient, each character formed by a plurality of pixel elements. The pixel elements may be formed by designing a pattern of dots on a computer system using graphic software for representing the resulting pattern in a machine-readable graphics file. The graphics file is used to control a compatible imagesetter machine for forming the desired pattern on photographic film. According to an alternative method, a film master is prepared in which each pixel is a solid black dot. The test card is prepared by printing the image onto photographic paper through a diffusion element so as to create an approximately Gaussian light return profile across each pixel.

Abstract: A visor includes thin, flat, opaque member. The rear of the member is concave to conform to a wearer's forehead. There is means for mounting the visor on the top of a pair of eyeglasses so the member extends forwardly in front of the eyeglasses and rearwardly to the wearer's forehead. The means may be a pair of spaced-apart clips extending from the bottom of the member intermediate the front and the rear thereof. Each clip has a bottom, an aperture above the bottom and a slit extending from the aperture to the bottom of the clip. The slit is narrower than the aperture. The top of the frame of a pair of eyeglasses is receivable in the aperture of each clip to secure the visor to the eyeglasses.

Abstract: An apparatus for observing and photographing a corneal endothelium includes an illumination optical system 28 for projecting each illumination light emitted by a light source 30 for observation and a light source 32 for photography onto a cornea C of a subject's eye E at an angle, an observing and photographing optical system 29 for receiving scattered light reflected by the cornea C with the endothelial layer and observing and photographing it, and an optical system 1 for observing the anterior segment of the eye E. The observing and photographing optical system 29 is provided with a sensor 47 for detecting an image of the endothelium in focus.

Abstract: A virtual image display optical system. The system includes an image source, a combiner, and a relay group. The relay group is a catatrioptic relay group that includes a reflective optical element, and a refractive lens group that includes at least one doublet and a diffractive lens. For some applications, the catatrioptric relay group may be replaced by a hybrid refractive-diffractive relay group, thus eliminating the reflective element. The diffractive optical element of the hybrid optical element is encoded on one side of a lens. The hybrid optical element forms a refractive/diffractive achromat to provide for primary chromatic aberration correction. The refractive lens group is also an achromat to provide for chromatic aberration correction. Power distribution between the hybrid optical element and the refractive lens group is such that secondary chromatic aberration of the refractive lens group is balanced out by the secondary chromatic aberration of the hybrid optical element.

Abstract: Techniques and retinoscopic apparatus for measuring or determining a patient's optical error are disclosed. The techniques include overrefraction and can be performed from a fixed position, avoiding the practitioner's need to move back and forth relative to the patient's eye. Equipment associated with the apparatus is adapted to record the location of the retinoscope slide (relative to its upper or lower position) during the examination to provide information concerning the optical error present in the patient's eye.

Abstract: A new and improved pen and glasses combination with a first eyeglass component having one receiving arm with an oblong recess therein. A tapered extension is integral with the recess. A female detent element is secured to the recess. A curved ear component has an externally threaded extension and is secured thereon. The curved ear component functions to fit over a wearer's ear. An attachment component has an internally threaded aperture therein. The internally threaded aperture corresponds with the externally threaded extension of the curved ear component. An implement extension is integral with the attachment component. A male detent element is secured to the implement extension. The male detent element corresponds with the female detent element of the oblong recess of the first eyeglass component to lock the attachment component with the first eyeglass component. An oblong recess is formed in the implement extension. A pen component is secured within the oblong recess formed in the implement extension.

Abstract: A diffraction grating providing an optically variable image includes a pixellated diffraction grating in which each pixel is an individual optical diffraction grating so that the pixellated diffraction grating when illuminated generates an optically variable image. In another aspect the grating in some or all of the pixels of a diffracting grating formed by a regular matrix of pixels is arranged such that a reproduction of the grating by reflection contact printing generates a zero-order pattern which is grossly flawed by Moire or Talbot fringe effects. A method of forming the diffraction grating includes producing a counterpart pixellated diffraction grating of a substantially optically invariable image wherein each pixel of the optically invariable image is maped to a respective pixel of the pixellated diffraction grating.

Abstract: Protective eyewear for sports activities and the like having a resilient rigid frame is disclosed. Included is a sealing area around the eyes having a web which diverges outwardly in every direction toward the lens frame. The frame is curvedly contoured around the face of the user and in conjunction with the diverging web, provides both maximum eye protection and peripheral visibility. A semi-rigid frame provides for temple mounting and obviates the need for around-the-head straps.