Abstract: An eyeglass lens trimming machine includes spring arrangements operative between a carriage and a chassis to urge the carriage towards an associated feeler. The feeler being mobile on the chassis, auxiliary spring arrangements between it and the carriage also urge the carriage towards the feeler.

Abstract: A grinding machine for grinding eyeglass lenses includes at least one grinding wheel rotatably mounted on a chassis. A carriage is pivoted to the chassis to pivot about an axis parallel to the rotation axis of the grinding wheel. A support spindle is rotatably mounted on the carriage to rotate about an axis also parallel to the rotation axis of the grinding wheel and which is adapted to receive axially the lens to be ground and a template. A feeler in vertical alignment with the template is mounted on the chassis so that it is movable transversely relative to the pivot axis of the carriage. The feeler comprises a rigid pad and a tactile sensor appropriately attached to the rigid pad, at the surface thereof.

Abstract: To define a far vision area and a near vision area in a simultaneous vision ophthalmic lens for correcting presbyopia, the curve representing the proximity as a function of the distance from the axis lies within an area between a lower envelope curve and an upper envelope curve with associated specific polynomial equations in which the coefficients depend on the proximity addition corresponding to the degree of presbyopia of the wearer. Either the far vision area or the near vision area is strengthened relative to the other, the corresponding surface areas S.sub.VL, S.sub.VP being related as follows:for strengthened near vision:1.8.ltoreq.S.sub.VL /S.sub.VP .ltoreq.3.6and for strengthened far vision:4.75.ltoreq.S.sub.VL /S.sub.

Abstract: A display container for eyeglass lenses includes a plate to receive the eyeglass lens to be displayed and two half-shells pivoted to the edge of the plate about a pivot axis globally perpendicular to the plate. Each half-shell can move between a closed position wherein, juxtaposed to each other, they conjointly form a protective shell around the plate, and an open position in which they uncover the plate. The plate has a globally circular contour, has no rim over at least part of its edge and has locally projecting from it at least three locking pegs for holding the eyeglass lens.

Abstract: A method for making a thermoplastic optical lens having at least one side coated with a thermosetting protective film is provided. The method includes steps of applying a thermosetting coating composition to a molding surface of the molding shell, disposing the thermoplastic lens blank in a horizontal position and vertically above the molding shell, heating the lens blank to cause thermal sagging under low static load conditions as the lens blank comes into contact with the coating composition on the molding surface and continuing heating until the lens blank mates with the molding surface.

Abstract: A method of checking that a lens suits an eyeglass frame uses the lens grinding machine itself. The lens to be ground is mounted on a support shaft and moved into contact with the grinding wheel with the latter stationary. The support shaft is rotated stepwise until the lens to be ground has rotated through one complete turn. A check is carried out to determine whether a feeler associated with a template is operated thereby during such rotation. The invention finds an application in grinding machines used to trim eyeglass lenses.

Abstract: An eyeglass frame has rims or surrounds at least locally made from a relatively rigid material. They have in transverse cross-section over at least part of their length a U-shape profile with a median part and side flanges. A strip of relatively flexible material is associated with each rim or surround and is disposed between it and the respective lens. The median part of the profile of the rims or surrounds has an increased thickness in its median area.

Abstract: An optical system is adapted to conjugate an object plane with an image spherical dome whose radius is less than its focal length and whose exit dioptric is a spherical dome on which the image spherical dome is substantially superimposed. The optical system can be used in an exposure device for modifying by physical-chemical treatment the power profile of an artificial optical lens made from a photopolymerizable material. The device comprises a source of radiation and between the source of radiation and the artificial optical lens to be irradiated a mask adapted to modulate the energy flux spatially. The exposure device comprises a curved field lens system formed by the optical system.

Abstract: In a method of manufacturing a transparent polymer material article having a refractive index gradient the polymer base material is caused to absorb a swelling agent including at least a monomer adapted to yield a polymer having a refractive index different than that of the polymer base material. A first preform having a first geometry is formed from the polymer base material sufficiently polymerized for the first preform to be self-supporting. A confinement space is defined between the first preform and an abutment member having facing it a second geometry at least partly different than the first geometry and having a greater volume than the latter. The first preform is brought into contact in the confinement space with a sufficient quantity of swelling agent for the swelling to which it is then subject to cause it to be urged actively into contact with all points of the second geometry.

Abstract: The front surface, for example, of a progressive ophthalmic lens has a central area whose curvature varies progressively over at least part of at least one meridian and constitutes its optically active area. Surrounding this central area is a peripheral joining area merging tangentially with it. The optically active central area of the front surface is delimited by a closed curve which, when projected onto a plane perpendicular to the geometrical axis of the lens, is generally oval shape. The value and/or sign of the radius of curvature of the radial cross-section of the peripheral joining area varies in the circumferential direction so that the thickness of the lens is substantially the same all along its peripheral edge. Progressive ophthalmic lenses of this kind are easier to manufacture, lighter in weight and more esthetic.

Abstract: A device for fastening a holding part on an eyeglass frame placed on a plate comprises an arm adapted to receive removably the holding part and a carriage on which the arm pivots between a raised loading end position and a lowered fitting end position. The carriage is mobile on a frame in a straight line between a retracted rest end position and an advanced end of travel position. A transmission system operative between a drive system and either the arm or the carriage is such that, at least when the carriage is in the vicinity of its advanced end of travel position, the arm is in its retracted fitting position. A locking device is operative between the arm and the carriage to lock the arm releasably to the carriage when in its lowered rest position.

Abstract: A method for reading the shape of any elastically deformable article uses a contact feeler to follow the shape to be read. The contact feeler is applied to the article with a force of particular value adapted to cause localized deformation of the article and the coordinates of the contact feeler are noted at the relevant time. Two successive coordinate readings are systematically carried out, one with a first non-zero set point value of the contact feeler application force and the other with a second non-zero set point value of the application force different than the first set point value. The coordinates for a zero set point value of the contact feeler application force are deduced mathematically from the two coordinate readings.

Abstract: A device for fitting a holding part onto an eyeglass lens comprises a plate adapted to receive the eyeglass lens pivoted to a fixed base and a calibrated spring arrangement and a displacement sensor operative between the plate and the base.

Abstract: The manufacture of an artificial optical lens having any given power profile starts from an artificial optical lens having a different power profile. A physical-chemical treatment method modifies the power profile to obtain a required power profile. A rotating mask is used for spatial modulation of the energy flux.

Abstract: A contour follower device suitable for reading off the contour of eyeglass frame rims or surrounds includes a support table with holding means for supporting the article whose contour is to be read off. A feeler has a rotatable contact head adapted to be applied to the article and is carried by a carriage which is movable relative to the support table. The contact head is rotated by rotational drive means such as a motor-gearbox unit.

Abstract: To determine the focal power of an ophthalmic lens, a plurality of light rays are passed through the lens and a photosensitive position sensor is disposed on the exit side of the lens to measure the coordinates of the points at which the light beams impinge on an analysis plane perpendicular to the lens axis. The light rays comprise three light rays on a circle and a light ray on the system axis.

Abstract: In a method of forming an ophthalmic lens from a synthetic material blank, in particular from a polycarbonate material, the blank is placed horizontally in a mold having optically finished molding surfaces. It is then subjected to a molding force at raised temperature in an oven. The mold has an upper molding surface that is part of a shell member adapted to slide freely in a ring. The molding force is limited to the static force due to the weight of the shell member, optionally increased by the weight of a pre-load mass surmounting the shell member.

Abstract: A support device for eyeglass frames whereby the contour of one or both rims or surrounds of the frame can be read comprises a plurality of retaining means on a plate and on a flap pivoted to the plate. The retaining means are adapted to hold an eyeglass frame above a hole in the plate. The flap is pivoted to the plate and its inclination relative to the plate is adjustable.

Abstract: To produce a graded index polymer there is diffused into a base material formed of at least one partly polymerized monomer adapted to yield a homopolymer with refractive index N1 in the gel state an additive material formed of at least one monomer adapted to yield a homopolymer with refractive index N2 different from N1. The polymerization of the base material treated in this way is then completed. The additive material comprises a mixture of at least two monomers and the composition of this mixture is varied with time.

Abstract: A device for fastening a holding part on an eyeglass lens placed on a plate comprises an arm adapted to receive removably the holding part and a carriage on which the arm is able to pivot between a loading and offloading position and a fitting position. The carriage is mobile on a frame between a rest position and an end of travel position over a path on which the arm is brought into alignment in the fitting position with the plate. The carriage is at least in part adapted to move in a straight line in a first direction controlled by a guide fastened to the frame and the pivot axis of the arm is in a second direction orthogonal to the first direction. A belt and gear transmission is operative between the carriage and the arm to move the arm from one end position to the other.