Abstract: Apparatus for determining the diameter of an unprocessed ophthalmic lens to fit a particular eyeglass frame comprises a base and a guide on the base adapted to receive a card carrying diagrams of available lenses. A support on the base is adapted to receive the eyeglass frame to be fitted with lenses. The card guide is fixed relative to the base and comprises an elongate slot adapted to allow the card to slide within it. The frame support is mobile relative to the card guide in the direction at right angles to the slot.

Abstract: A device for measuring a subject's ocular parameters, in particular the interpupillary distance, comprises a front plate against which the face of the subject is placed, comprising two windows substantially corresponding to the lenses of a pair of eyeglasses. A lens is movable along its optical axis, which is perpendicular to the front plate, from an origin position near the front plate. A viewing eyepiece is disposed at the focus of the lens when in the origin position. A semi-reflecting mirror disposed at 45.degree. renders the eyepiece and a point source coincident, as far as the subject is concerned. Parallel to the semi-reflecting mirror, another mirror reflects an image of a cathode ray tube screen to the eyepiece through another lens. Adjustable calibrated voltage sources are used to produce coincidence of the reflections of the source on the corneas of the eyes of the subject and the luminous traces on the screen of the cathode ray tube, as seen by an operator looking through the eyepiece.

Abstract: A machine for grinding ophthalmic lenses comprises a frame and a support to which an ophthalmic lens to be processed may be attached pivoted to the frame about an axis parallel to the axis of the grinding tool. A counterweight on the support is movable relative to the frame in a direction orthogonal to the pivot axis. A drive device controls movement of the counterweight. A guide cam is disposed on the path of movement of the counterweight. The machine may be used for trimming and/or bevelling or grooving an ophthalmic lens.

Abstract: The peripheral edge of an ophthalmic lens is maintained in contact with a bevelling or grooving wheel while being rotated about an axis of the lens parallel to the axis of the bevelling wheel whereby a bevel or groove is formed in said peripheral edge. The ophthalmic lens is capable of relative axial displacement relative to said bevelling wheel. By way of a force or displacement sensor, the relative axial position of the ophthalmic lens with respect to the bevelling wheel can be made subject to the axial component of reaction forces generated between the lens and the bevelling wheel in their mutual contact zone.

Abstract: A lens holder device is employed having a bell-shaped chamber, at least a portion of the sidewall of the chamber at an open end thereof having a circular section and adapted to accommodate with radial clearance a lens to be surfaced. A conduit communicates with the chamber and supplies pressurized hydraulic fluid into the chamber. The pressurized hydraulic fluid in the chamber forms a hydraulic cushion for the lens, and a hydraulic film flowing between the peripheral edge of the lens and the sidewall portion, the hydraulic film flowing out of the open end of the chamber.

Abstract: In a method for bevelling an ophthalmic lens, the lens is rotated about its own axis and is also displaced parallel to its axis as a function of its angle of rotation. Simultaneously, the edge of the lens is kept in contact with a grinding wheel. Thus the point of contact of the lens with the grinding wheel is constrained to follow a specific path. The specific path to be followed by the point of contact is an intermediate path selected between two paths resulting from a comparison between a collection of predetermined paths and two reference paths. The reference paths are each obtained from a plotting operation carried out prior to the bevelling operation on the ophthalmic lens using feelers. This method is used in grinding machines such that trimming and bevelling of ophthalmic lenses can be automatically performed.

Abstract: A device suitable for molding ophthalmic lenses comprises two spaced mold parts in face-to-face relationship inside a cylindrical sleeve. One or both parts comprise a rigid supporting base, a molding die of an elastically deformable material and an intermediate pad of an incompressible elastic material disposed between the base and the die and completely covering their respective surfaces.

Abstract: Apparatus for displaying eyesight tests for patients comprising a viewing station a test support having a plurality of eyesight tests selectively visible from the viewing station along first and second optical paths, the first optical path being for near vision and devoid of optical focusing means and the second optical path being for far vision and having optical focusing means. The optical paths have a common section running from a selected test support panel. Each of the optical paths comprises a mirror for bending the viewing axis toward the viewing station, the mirror for the first optical path being rockably mounted or semireflecting for providing access to the second optical path.

Abstract: As in the conventional manner for molding an optical component, a molding cavity is used in combination with a relief chamber with which the molding cavity can selectively communicate. There is no communication between the relief chamber and the molding cavity while the latter is filled. The molding cavity is then placed in communication with the relief chamber. Subsequently, relative displacement of the relief chamber and the molding cavity parallel to the axis of the combination interrupts such communication. The optical component thus molded may be of any kind, such as an optical lens, specifically an ophthalmic lens.

Abstract: A contact lens has a rear surface, a front surface and a peripheral edge surface extending between the front and rear surfaces. The peripheral edge surface extends generally forwardly and obliquely from the rear surface to the front surface. The invention is more particularly, but not exclusively, applicable to flexible contact lenses, such as contact lenses manufactured of silicone and similar materials, for example.

Abstract: An ophthalmological surgical device comprises a laser unit (10) adapted to emit at least one laser beam (F) and an operating unit (11) adapted to focus the laser beam or beams (F) on an aiming point (0). The operating unit (11) incorporates a focusing lens (36) and a mirror (37). These are mounted on a supporting chassis (16) adjustably mounted on a base (24). First control device accessible to the operator control the position of the chassis (16) on the base (24). The lens (36) and mirror (37) are together mounted on an assembly (40) in turn mounted on the support chassis (16). The assembly (40) is movable relative to the chassis (16) under the control of second control device separate from the first control device.

Abstract: An eyeglass frame comprises a main support structure, a pair of rims each comprising a relatively rigid upper rim member and a flexible tie attached at its ends to the upper rim member. The nose pads have grooves for receiving them on inner terminal parts of the respective upper rim members. There are two transverse holes in the terminal part of each upper rim member. A passageway continues each groove through a land in each nose pad. The ends portion of each tie is threaded upwards through the passageway and then through the holes in the upper rim member for attachment thereto. The inner surfaces of the nose pads bearing against the wearer's nose have no recesses or the like for collecting dirt or grease.

Abstract: An ophthalmic surgical apparatus is disclosed comprising a main laser generator for emitting an operating laser beam of infrared energy and an auxiliary laser generator for emitting a marker laser beam of visible light. The laser beams are superposed before reaching an operating system by a plurality of mirrors and a laser beam expander for each of the laser beams. The laser beam expanders have separate entrance lenses and a common exit lens. Preferably, the operating optical system comprises a focusing lens which doubles as the common exit lens of the laser beam expander.

Abstract: Multifocal ophthalmic lenses are disclosed such as a bifocal lens in which the convex front surface includes an upper part for distant vision having a first spherical surface and a lower part for reading having a second spherical surface, the radius of the first spherical surface being greater than the radius of the second spherical surface. A zone of curvature continuity connects the first and second spherical surfaces along at least one meridian, e.g. a central meridian, of the ophthalmic lens, and the second spherical surface extends away from the zone of surface continuity into a surface of revolution which may be spherical or toroidal. Junctions between the surfaces are defined by ledgeless intersections which are lines of curvature discontinuity extending away from the zone of surface continuity.

Abstract: In a spectacle frame each lens surround is formed by a relatively rigid rail and a flexible retaining member attached at each end to the rail. To effect this attachment the ends of each rail are formed with two transverse holes through which the flexible retaining member is passed twice. Each nose pad of the spectacle frame is also formed with two transverse holes through which the flexible retaining member may be passed twice. The holes in each nose pad correspond to those in the nose end of the associated rail, so that the nose pad may be attached to the rail by means of the flexible retaining member holding a lens in position in the surround.

Abstract: A progressive opthalmic lens is disclosed which has an upper part of constant refractive power for distance vision and a lower part of progressively variable refractive power for near vision. In order to increase the effective field of intermediate vision while providing smooth transition between the upper and lower parts of the lens for the user, an additional segment providing a local addition of refractive power is superposed on at least a portion of the progressive variable power zone of the lens. The additional segment may comprise an insert or a protuberance on the progressive portion which may be formed as a surface film on a blank base or substrate. The additional segment may have constant refractive power or include a progressively variable refractive power area.

Abstract: An eyeglass frame with a detachable frame front is disclosed. The eyeglass frame comprises a main frame structure including a main cross bar and hinged temples at its ends, and the separate, detachable frame front comprises rims interconnected by a pair of parallel cross members defining a bridge. A fastener member or pad is secured to the underside of the main cross bar and has a pair of parallel grooves cooparable with the cross members for releasably securing the latter in position. One of the grooves is along the front surface of the fastener member and the other groove lies along the lower surface thereof. The fastener member also has one or more apertures cooperable with teats on an additional (sun) frame front for releasable securing the latter. Alternatively the additional frame front may be pivotally mounted on the fastener member.

Abstract: A spectacle frame comprises a crossbar and a removable lens holder comprising a central bridge, side pieces joined by the bridge retaining respective lenses. The bridge mates with a central section of the crossbar to removably attach the lens holder to the crossbar. The bridge comprises two branches curved in opposite senses, substantially in alignment with the side pieces, to constitute as plane closed loop. The branches of the bridge carry resilient retaining clips which engage co-operating edge portions of the central section of the crossbar.The central section comprises two branches curved in opposite senses and joined together to constitute a substantially plane closed loop analogous to and superposable on the closed loop formed by the curved branches of the bridge.

Abstract: A dummy lens for molded-to-shape eyeglass frame front molds including mold halves defining rim forming channels and a central bridge forming channel. The dummy lens comprises a lenticular disc having a periphery ridge adapted to define the groove for the ultimate ophthalmic lens and an axial projection extending from the concave side of the disc and having a cylindrical portion for centering the dummy lens and a tapered portion at its free end defining a draft. The disc and the tapered free end of the dummy lens bear against respective opposed plateaus of the half molds.