Abstract: A hologram is formed using a grating and a second hologram serving as an image hologram. The grating is constituted by a plurality of areas whose spatial frequencies and diffraction directions are different from each other. This grating is formed using a grating array and a mask. The second hologram has a plurality of areas each of which records information or image (e.g., ID data) serving as a recording target as an element hologram. The second hologram is formed using a Fresnel hologram serving as a first hologram. The first hologram can also be formed using a mask and a diffuser on which ID data is projected. On the hologram, information (pattern or image) is recorded with each of reference light components having different directions corresponding to the different small areas. Even if illumination light having a uniform wavefront is irradiated on this hologram, it is difficult to detect all the information (pattern and image).

Abstract: In a cornea shape measuring apparatus wherein a chart for measurement is projected onto the cornea of an eye to be examined and the shape of the corneal reflection image thereof is detected through a measuring optical system to thereby measure the shape of the cornea, there is provided an observation optical system for enabling the corneal reflection image to be always observed. The magnification of the observation optical system is made smaller than the magnification of the measuring optical system and the fore eye portion and the corneal reflection image are always observable.

Abstract: An eye fundus observing and photographing apparatus has an illuminating optical system for supplying illuminating light to an eye to be examined, an optical system for observing and photographing the fundus of the eye to be examined through an observation aperture stop, and an objective lens common to the illuminating system and the observing and photographing system. The objective lens is comprised of a first component which is a cemented positive meniscus lens having its concave surface facing the eye to be examined and a second component which is a cemented positive meniscus lens having its concave surface facing the observation aperture stop. The center of curvature of the concave surface of the first component which is adjacent to the eye to be examined is coincident with a position conjugate with the observation aperture stop with respect to the entire objective lens.

Abstract: An eyeglass frame is disclosed which comprises a monolithic, one piece front member fabricated of thermoplastic resin and having a unitary brow bar and a pair of lens rims depending therefrom, there being an elongated reinforcement member fully embedded within said front member.

Abstract: Spectacles formed by combining two separate parts, respectively, a support structure connected to spectacle temples and a detachable front.A bridge of the front is adapted to be joined to the central part of the support structure connecting the two spectacle temples through the intermediary of a assembly element. Each of the edges of the front is adapted to be connected to the support structure close to its connection with the temples through the intermediary of a projecting assembly element cooperating with a hold-back device and a housing.Application to the realization of the connection of a front and a support structure ensuring good interlocking and insertion of the hooking elements in the overall aesthetic appeal of the spectacles.

Abstract: An eye-examining apparatus comprises a first positive lens unit, a negative lens unit, a second positive lens unit, a third positive lens unit and a target mark arranged in the named order from the side of the examined eye. The third positive lens unit is mounted movably along the optical axis. Between the first and second positive lens units there is interposed on astigmatic system rotatable about the optical axis. The negative lens unit, the second positive lens unit and the third positive lens unit are so arranged as to form an image of the mark at a position near the focal point on the target mark side of the first lens unit. The focal point on the examined eye of the composite system composed of the negative lens unit, the second positive lens unit and the third positive lens unit is approximately coincident with the position conjugate with the pupil of the examined eye relative to the first positive lens unit.

Abstract: A binocular opthalmoscope, having an optical viewing system, a light source and headgear mountable on an examiner's head during use for supporting the optical viewing system in optical alignment with the examiner's eyes and the light source with the output thereof above the optical viewing system. The light source has a selector for for selectively providing both full beam and slit beam illumination of a patient's eye, a first condensing lens for focusing light on the bull beam or slit beam aperture, a second condensing lens for refocusing the light passing through the aperture onto an aerial image of the retina, and a third lens for shortening the focal length of the beam emitted from the light outlet of the light source and which is mounting for pivotal movement into and out of the beam path.

Abstract: The present invention relates to an apparatus for eye sight examination, allowing to test both of the patient's eyes, especially to detect his common failures and vision defects, for far and close vision, and eventually intermediary distance vision.The test-image are borne by at least one ribbon or band mounted in a block of two winding spools, housed in a body forming an easily removable tape box of an adequate support of body of the apparatus.The invention applies to the automatic or semi-automatic detection of visual defects of a patient.

Abstract: A lens assembly including an adjusting mechanism arranged to render a part or parts of or all of the optical elements, constituting an optical system, movable by an electric motor drive arrangement, the lens barrel is composed of a stator or stators of one or a plurality of linear motors for driving the adjusting mechanism. The movable element of the linear motor corresponding with the stator is formed into a hollow space, in which each of the movable optical elements can be accommodated.