Abstract: The invention contemplates an improved ophthalmological instrument wherein photo slit-lamp function (for anterior-chamber examination of an eye) are combined with fundus-camera functions (for posterior-chamber examination of the eye), with important advantages of manipulating convenience and reduced cost. The invention is disclosed (a) for the case of a photo slit-lamp accessory for use with an existing fundus camera and (b) for the case of a more compact new instrument to serve both functions.

Abstract: The invention provides an ophthalmological technique and instrumentation for making better and more facile examinations of the anterior portion of an eye, by employing a known interference-contrast technique in on-axis combination with an illumination-source, and having the feature of binocular-microscope viewing. In the form described, polarized light from the source is introduced to the microscope-objective axis at a location between a Nomarski prism and the associated analyzer of the interference-contrast system. This polarized light passes through the Nomarski prism and the microscope objective enroute to the eye being examined; from the eye, it is reflected back through said objective and prism to the analyzer, where a beam-splitting prism serves the respective ray paths of a binocular-microscope viewing system.

Abstract: An optical system for microscopes to enable microscopes having objectives of infinite exit vertex focal length to be made compatible with microscopes having objectives of finite exit vertex focal length, and vice versa, thus enablying the microscope user having a microscope of one kind to continue to use his supply of interchangeable objectives if he acquires a microscope of the other kind, and enabling microscope manufacturers to stock only one style of objective even if both styles of microscopes are being manufactured or if a transition is being made from one style to the other. The invention provides adapters having optical elements which enable an objective of the finite exit vertex focal length kind to be used with a microscope designed for an objective of the infinite exit vertex focal length kind, or vice versa, the optical system of the adapter providing adequate compensation or correction for aberrations.

Abstract: The invention contemplates a modular system of interchangeable and multiply-combinable objective-lens components for selective use with an operation microscope to enable improved viewing of small operational areas, particularly in areas which are in deep channels or recesses. The construction permits optional use of the instrument in the context of stereoscopic or split-beam binocular viewing, or as an endoscope. Viewing is enhanced by efficient light transmission of both (a) the light used for object illumination and (b) the optical transmission of the image to be viewed.

Abstract: The invention contemplates an improved optical system for illuminating the retina or ground of the eye and having particular application to a hand-held ophthalmoscope. The optical system, thus embodied, permits selective modification of image scale, for a test mark or marks projected in the eye. Two embodiments are disclosed.

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: An ophthalmological instrument having optical elements providing an examination light beam path and an illumination light beam path. The optical elements include an objective for producing an inverted magnified flattened image of the fundus of the eye, and further elements for focusing this image at infinity and projecting it selectively either into an observation tube or into a camera or other documentation device where a record of the image may be made. The illumination beam path includes a source of light and means of projecting this light, via a perforated mirror, into the pupil of the patient.

Abstract: An ophthalmological instrument for stereoscopic examination of the fundus or retina of the eye of a patient, and documentation thereof, as by photographing it. The instrument provides an observation light beam path, and an illumination light beam path. In the observation beam path are various optical elements for producing an image of the fundus at appropriate places, and a beam splitter to split the beam into two parts for stereoscopic viewing. A movable deflector can be shifted to a position to deflect at least part of the beam to a camera or other documentation device.

Abstract: A wide angle objective intended especially for visual and photographic examination of the fundus of the eye. Each of the separate lens elements which together make up the objective is so designed that one surface of the element provides the desired refractive power and the other surface of the same element is concentric with the locus of the pupil produced by the surface bearing the refractive power. Also, the objective is so designed that black points are arranged at the locus of the ghost reflections of the mirror conjugated with the pupil of the test subject which are produced in the objective, thereby suppressing disturbing reflections.

Abstract: A hand-held ophthalmoscope having a handle part and a head part, with an illuminating device in the handle part. In the head part is an imaging lens system for producing an image of the fundus of the eye being examined, and an axially displaceable optical system for focussing the image of the fundus at infinity. The illuminating device in the handle has a source of light and a condenser and a field diaphragm. There is an optical system for imaging the field diaphragm in the key of the patient. A test mark is pivotally mounted on the mount of the axially displaceable optical system in the head portion of the device, and may be moved into cooperative relation to a scale. Preferably the optical system for producing the image of the fundus, and the partial optical system for imaging the field diaphragm or the test mark, have the same focal length.

Abstract: An optical system in which at least one of the elements is made from so-called gradient glass having a radial difference in refractive index. The element having this radial difference may be either a lens with at least one curved surface, or a plane-parallel plate. The radial variation in refractive index varies in accordance with a formula which is given.