Abstract: A tracer is provided for tracing a lens mount of an eyeglass frame, a lens or a lens pattern. The tracer comprises an object engager and an actuator. The object engager is adapted to engage the lens mount, the lens or the lens pattern. The actuator is adapted to move the object engager into contact with and then along the lens mount, the lens or the lens pattern in such a way that during movement therealong, the object engager remains against the object being traced even when the shape thereof includes high wrap. Preferably, the tracer has a shift mechanism adapted to shift the object engager from alignment with the lens mount to alignment with a second lens mount of the eyeglass frame. The actuator preferably is further adapted to trace the second lens mount in substantially the same way as the first. The actuator further includes a rotator and a pivot mechanism. The rotator is adapted to rotate the object engager along the object being traced.

Abstract: Apparatus for tracing the perimeter shape of the lens holding aperture of an eyeglass frame, or an eyeglass lens, includes a holder to releasably hold an eyeglass frame or lens for tracing measurement. A tracing stylus has a 3 axis movement control apparatus to move the stylus around an axis of rotation and in a vertical and a horizontal direction of a plane rotatable about the axis of rotation. The stylus is urged into horizontal contact with the frame or lens to be traced by a horizontal axis motor dynamically controlled to optimize the contact force between the tracing stylus and frame or lens during the trace process. Control of the vertical movement axis of the stylus optimally provides a weightless behaviour of the stylus permitting it to move vertically responsive to external vertical forces.

Abstract: In a target lens shape measuring device for measuring a target lens shape used to process an eyeglass lens, movement of a feeler in a radius vector direction is detected by a first detection system, and movement of a holding base by a moving system is detected by a second detection system. Calibration data is obtained based on the detection result by the second detecting system during the movement of the holding base by the moving system, and the detection result by the first detecting system is calibrated based on the obtained calibration data.

Abstract: The present invention relates to a measuring instrument for establishing the mounting lens angle of a spectacle mount, comprising

Abstract: The proposed invention calculates the circumference of an optical lens taking into consideration external variations in lens size and shape. The invention, utilizing a uniquely designed optical lens tracing pen in conjunction with a specifically designed tracing template provides for a consistent method of measure with respect to the outermost ridge of a traced lens. The lens is traced utilizing the specifically designed invention pen, and scanned into a software system which receives the traced image and plots a lens shape based upon a calculated distance between first color template axis indicators and a second color pen tracing. The system further provides for a number of options to allow specification a prescription to be utilized in conjunction with the lens sizing information as well as the automated and transparent downloading of computer software and additional lens shape offerings reflected in updated versions of the invention.

Abstract: To provide a template holder in which parts such as screws for mounting a template to a template mounting member is not lost. A template holder, in which in a state in which an elastic strut 94 is inserted into a holding hole 81 of a template 80, is pressed and is caused to abut upon an end surface 91a of a base member 91a by the elastic strut 94 by operating a pressing strut 95, whereby while the template 80 is mounted to a holding member 91, the holding member 91 is departed from the template 80 by operating the pressing strut 95 to thereby enable the template 80 to be removed from the elastic strut 94 and the holding member 91, wherein the pressing strut 95 and the elastic strut 94 are held by the holding member 91 when the template 80 is attached and detached.

Abstract: The accuracy of the axial degree of a lens in an eyeglass production is improved. In an eyeglass frame measuring apparatus, first and second frame data on the eyeglass frame consisting of first and second frames are entered. The entered first frame data are inverted to obtain a third frame data. On the basis of the third frame data and the entered second frame data, an amount of deviation of the second frame data with respect to the third frame data in a rotation direction is obtained. An eyeglass lens is processed on the basis of the rotation deviation amount and the third frame data.

Abstract: A control system is provided for a pivotally actuated tracer which traces an object (e.g., a frame mount of an eyeglass frame, a lens, or a lens pattern) while the object is held in a more-vertical-than-horizontal orientation. The control system comprises a trace control element and a gravity compensation element. The trace control element applies control signals to the pivotally actuated tracer. In response, the object engager of the tracer is pivotally actuated against and along the object to be traced with a biasing force toward the object. The gravity compensation element is adapted to compensate for the effects of gravity on the object engager by causing a varying pivoting force to be exerted on the object engager. The pivoting force varies depending on the rotational orientation of the object engager to keep the biasing force substantially constant along the object. Also provided is a data acquisition system for the tracer.

Abstract: An apparatus is provided for measuring the contour of a lens frame of an eyeglass frame and measuring the shape of a template. The apparatus has at least a pair of holding hooks (43, 44) for holding the rim of the eyeglass frame from above and below. The apparatus is constructed to hold a template holder (100) of a template (T) by the holding hooks (43, 44).

Abstract: A holding assembly for holding spectacles, having an adjustable grip for fitting around a pair of spectacles. The adjustable grip is slidably mounted to allow alignment one after the other of each lens along a single predetermined axis perpendicular to the plane of the lens, such that the aligned lens has a clear line of sight to a lens measuring device.

Abstract: An apparatus, for reading the groove contour of spectacle frame rims, which includes first and second bearer structures for holding the spectacle frame, a first groove-contour-reading set, a second groove-contour-reading set, and a drive motor. Each of the first and second groove-contour-reading sets includes a first contact member for engaging the groove in one of the spectacle frame rims, a first guide member for guiding the movement of the contact member, and a reading member for reading the movements of the contact means. Further, the apparatus includes a drive motor for simultaneously driving the first and second contact members to thereby simultaneously read the groove contour in the two spectacle frame rims. Because the groove contours are simultaneously read, the apparatus reduces the time necessary to accurately measure the groove contour in each rim of a frame of spectacles.

Abstract: Methods for measuring the distance between an eye and a lens spaced apart from the eye include passing an elongated tubular structure between the eye and the lens, and causing a length of a wire member to pass out of the opening at a distal end of the elongated tubular structure. The length of the wire member extending out of the opening is selected so that the combination of the elongated tubular structure and the wire member extending out of the opening is located in close proximity to the eye and contacts the lens. This length of wire member extending out of the distal end is correlatable to the distance between the eye and the lens. Apparatus for providing such measurements are included.

Abstract: On a monitor (52) there is displayed a synthesized image (G4) in which an image (G1) of a subject lens showing a refractive power distribution, an image (G2) of a lens frame, and an eyepoint mark image (G3) are superimposed based on the refractive power distribution data of the subject lens by a lens meter (100), on the frame shape data of the lens frame by a frame shape measurement apparatus (200), and on the eyepoint data by an eyepoint measurement apparatus (300).

Abstract: Device and method for accurately recreating verification markings with removable ink on progressive ophthalmic lenses and molds are provided. The device includes (a) a stage which defines a coordinate system and which is adapted for receiving a lens or mold; (b) a magnifying device for locating the reference marks on the lens or mold surface; (c) a computer for storing coordinates from the platform wherein the coordinates represent the locations of two reference marks on the lens or mold surface; and (d) a pen device adapted to be positioned over the surface of the lens or mold wherein the pen device is controlled by the computer for applying the verification markings on the lens or mold surface.

Abstract: In a method of reading off the cross-section of the bezel of an eyeglass frame rim or surround at one point at least on the latter, a mobile feeler the position of which can be defined in a given system of coordinates is moved into line with the bezel. The head of the feeler successively sights at least two different points of at least one of the flanks of the bezel in order to deduce the coordinates of these points. The cross-section of the bezel read off in this way is used in trimming the lens to be mounted in the bezel.

Abstract: A contour reading device, in particular for eyeglass frames, includes a holding arrangement to support a template at a fixed position and a carriage mobile relative to the holding arrangement and carrying a feeler at the end of a rod. To read off the position of a mounting hole in a peripheral area of the template, the device includes a detector arrangement having at least one component constrained to move with the carriage at a given distance from the axis of the rod carrying the feeler, on the same side as a central area of the holding means. Applications include identifying the mounting holes in "drilled mount" eyeglass lenses.

Abstract: A calibration gage for calibrating a device for reading off the contours of eyeglass frames is designed to be fitted to the contour reading off device to be calibrated in place of an eyeglass frame. It includes a plate with at least two ribs projecting from it. The ribs are generally parallel to each other in a first direction and spaced from each other in a second direction. By reading off the known dimensions between their inside and outside flanks, it is possible to determine some parameters of the contour reading off device.

Abstract: The present invention measures the vertical and horizontal decentration of a pupil of a patient relative to a spectacle frame. The apparatus includes a housing having a distal end defining at least one target aperture. The housing has a proximal end opposite the distal end. An eye-piece is disposed at the proximal end and permits an operator to observe the pupil of the patient through the target aperture such that the eye-piece, the target aperture, the spectacle frame, and the pupil of the patient are in operative alignment. Also included is an adjustable left, right, and center vertical reference marker, each operatively coupled to the housing and horizontally displaceable relative thereto. The left and right vertical reference markers are configured to determine the position of a temporal edge and a nasal edge of the spectacle frame, respectively, while the center vertical reference marker is configured to be vertically aligned with the center of the pupil.

Abstract: An apparatus and method for subjectively (and in some cases at least partially objectively) determining the proper positioning of progressive power or other corrective lenses are disclosed. The apparatus includes a target such as a small fiber optic or other light source and one or more marking rods which may be activated by the patient (or, in some cases, by the practitioner). While wearing pre-fitted frames and fixating on a remote target, the patient (or practitioner) places the light source against or immediately adjacent the exterior surface of the simulated or other lens within either of the frames and positions the light so that it is centered in the patient's line of sight. Once the light is centered the marking rod is activated which contacts, and marks, the exterior surface of the lens.

Abstract: An apparatus for measuring pupillary height of a pupil of a patient relative to a spectacle frame includes a housing having a distal end defining at least one target aperture. The housing has a proximal end opposite the distal end. A eye-piece is disposed toward the proximal end and permits an operator to observe the pupil of the patient through the target aperture such that the eye-piece, the target aperture, the spectacle frame, and the pupil of the patient are in operative alignment. Also included is a means for establishing and maintaining the housing at a fixed position relative to the spectacle frame, and an adjustable lower platform operatively coupled to the housing and vertically displaceble relative thereto. The lower platform is configured to engage a bottom edge of the spectacle frame. A measuring scale is operatively coupled to the lower platform such that vertical displacement of the lower platform causes corresponding vertical displacement of the measuring scale.

Abstract: An apparatus for measuring the shape of a frame of spectacles is provided wherein the shape of a frame is measured with a measuring element which is held in contact with a groove in a rim of the frame while being moved along the groove. To accurately position the measuring element with respect to the groove of the frame before the start of measurement, positioning means is provided which moves the measuring element horizontally toward the frame, presses the measuring element against the frame with a biasing force, and which positions the measuring element at a measurement position. Further, to permit smooth vertical movement of the measuring element and to achieve accurate shape measurement, thrust means is provided which pushes the lower end face of a measuring element supporting shaft upward at a location displaced from the axis of the shaft.

Abstract: An apparatus for measuring a lens frame configuration is provided which comprises an apparatus body provided with a measuring reference surface, a frame holder movably retained by the apparatus body and adapted to hold right and left lens frames of an eyeglass frame so as to rotate and incline a holding plane of the lens frame with respect to the reference surface, a rotating device for rotating and inclining the frame holder, a measuring portion for measuring coordinates of each point in a circumferential direction of a V-shaped groove of the lens frame with respect to the measuring reference surface, and an arithmetic circuit for calculating an inclination of the lens frame in the V-shaped groove with respect to the reference surface from a result obtained by the measuring portion.

Abstract: A method is provided for custom manufacturing or fitting eyeglasses wherein a digital camera is used to take a series of digital images of selected portions of a subjects head, the images then being stored in a computer electronically associated with the camera, wherein the images contain frame and lens fitting information with respect to the size and shape of the subjects head, and thereafter providing a visual image display screen functionally associated with the computer for receiving and visually displaying the images such that an eyeglass frame and lens can be structurally and dimensionally configured in accordance with the fitting information.

Abstract: A design system for designing shapes of eyeglasses. In the system, image data expressing the face of a person are first subjected to image processing such as color compensation and profile emphasis. Subsequently, feature points representing the facial features of the face are extracted, and a plurality of horizontal, vertical and inclined auxiliary lines and auxiliary points on the auxiliary lines are set based on the feature points. Anchor points of a Bezier curve which defines the shapes of the lenses and frame of the eyeglasses are then determined. The Bezier curve is converted to data composed of polar coordinates, and the converted data are transmitted to machine tools. Control points provided at the anchor points are controlled based on words which represent a desired design image for the eyeglasses. The design system can automatically generates the shapes of the lenses and frames of eyeglasses based on features of individuals and their design preferences.

Abstract: An apparatus for measuring the shape of a frame of spectacles is provided wherein the shape of a frame is measured with a measuring element which is held in contact with a groove in a rim of the frame while being moved along the groove. To accurately position the measuring element with respect to the groove of the frame before the start of measurement, a positioning device is provided which moves the measuring element horizontally toward the frame, presses the measuring element against the frame with a biasing force, and positions the measuring element at a measurement position. Further, to permit smooth vertical movement of the measuring element and to achieve accurate shape measurement, a thrust device is provided which pushes the lower end face of a measuring element supporting shaft upward at a location displaced from the axis of the shaft.

Abstract: An arithmetic and control circuit 600 calculates an angle .theta. of inclination of one of lens frames 501, 501 of an eyeglass frame 500 from the maximum and minimum of height data Z.sub.n of frame configuration information L (.sub.o .rho..sub.n, .sub.o .theta..sub.n, Z.sub.n) about the lens frame (left lens frame) 501. If the angle .theta. exceeds a given angle .beta., the arithmetic and control circuit 600 adjusts a frame holder 100 holding the eyeglass frame 500 so as to make the angle .theta. smaller than the given angle .beta.. After that, the arithmetic and control circuit 600 again calculates height data Z.sub.n in the direction of a Z-axis relative to radius vector information (.sub.o .rho..sub.n, .sub.o .theta..sub.n) to obtain first true frame configuration information L (.sub.o .rho..sub.n ', .sub.o .theta..sub.n, Z.sub.n) about the lens frame 501 in three dimensional directions. Further, the arithmetic and control circuit 600 calculates a radius vector data difference .DELTA..rho..sub.n (.DELTA..

Abstract: An optometric apparatus for measuring optical characteristics of an eye to be examined comprising moving device for moving measuring section to adjust alignment with the eye to be examined, first and second deviation amount detecting devices for detecting deviation amount of the measuring section in a lateral and a vertical directions relatively to the eye at the time of measuring each of a left eye and a right eye to be examined, and correcting device for correcting data about an angle of astigmatic axis of the eye measured by the measuring section or interpupilary distance, based on the detected result obtained by the first deviation detecting device and the second deviation detecting device.

Abstract: A lens shape measuring instrument includes a slide base plate in parallel with a chucking shaft of an eyeglass lens, a flat contactor arranged on a first measuring bar disposed on a first rotating shaft, and a V-shaped contactor disposed on a second measuring bar disposed on a second rotating shaft, so that the flat contactor and the V-shaped contactor can be brought into contact with the peripheral surface of the eyeglass lens at the same time. The thickness center of the peripheral surface of the eyeglass lens can be detected by detecting positional change of the slide base plate, and the thickness of the peripheral surface of the eyeglass lens can be detected by rotation difference between the first rotating shaft and the second rotating shaft corresponding to the positional change and from shape of the V-shaped contactor.

Abstract: A method and apparatus for determining the size and shape to which a finished lens used to make an eyeglass lens is to be cut. Coordinates which define the outer perimeter of a lens are determined by illuminating either an eyeglass frame or a lens. An image of the shadow of the frame or lens is captured by an imaging device. A first linear polarizing filter is positioned optically between a light source and the membrane. A second linear polarizing filter, oriented at 180.degree. from the first filter, is placed optically between the membrane and the camera. Thus, the first and second polarizing filters allow a high definition image to be attained for substantially transparent plastic. A general purpose computer: (1) identifies the edges of the image so as to define the perimeter; (2) orients the image by identifying an orientation line placed upon a lens, if the image is of a lens which is not within a frame; and (3) measures the distance between lenses if an eyeglass frame is being measured.

Abstract: There is provided a frame measurement platform for measuring the perpendicular distance between the two temples of an open eyeglass frame, and a method for using such a device. The platform includes a support, two spaced-apart reference members which are moveable with respect to each other, and measuring scale. The reference members define respective temple measuring planes which are substantially perpendicular to a reference measuring plane defined by the support. The measuring scale is used to measure the perpendicular distance between temples of an open eyeglass frame.

Abstract: An ophthalmic measuring apparatus includes a device for measuring the distance from a certain point (such as the center of the other of right and left spectacle lenses or the bridge position of the lenses) to the center of the lenses on the basis of the amount of displacement of a spectacle lens contacting member, and a device for measuring the distance from a certain point (such as the center of the pupil of the other of right and left eyes to be examined or the nose position) to the center of the pupil on the basis of the amount of displacement of an observation system for observing the front eye parts of the eyes to be examined therethrough.

Abstract: The apparatus comprises a device which explores without contact the inner contour of the frame rim (16) and employs an optical device (30) for sensing the image of characteristic points of the rim inner contour, an analyzer for analyzing the sensed images for determining the spatial coordinates of the characteristic points, and a calculating device for reconstituting the shape and/or the profile of the contour of the frame rim from these spatial coordinates.

Abstract: A method is provided for fitting an eyeglass frame to a wearer. The method includes the steps of providing frames which have been classified into predetermined temple to temple size ranges based on the temple to temple frame sizes of the frames. The wearer's temple to temple head size is measured using a device which indicates at least one temple to temple size range as corresponding to the wearer. Eyeglass frames are fitted to the wearer selected from the frames which fall within the temple to temple size ranges corresponding to the wearer.

Abstract: A device for measuring the dimensions for locating multifocal segments on eyeglass lenses. A chinrest is provided for maintaining the stability of the patient's head while the proper location of the multifocal segment is determined, and an eyepiece is provided through which the dispenser may look at reference points on the face of the patient and the patient's new eyewear to measure the required dimensions. The eyepiece is then moved along the vertical axis of the post to which it is mounted, and the distance traveled by the eyepiece between the reference points is measured by a measuring device found on the apparatus.

Abstract: A lens meter for measuring the optical character of spectacle lenses by projecting a measurement target onto the spectacle lens comprises a first position control member for moving a spectacle frame in a horizontal direction, and a second position control member for moving the spectacles in a direction perpendicular to the direction of the first position control member. The position of the second position control member is detected by a potentiometer, and the pupilary distance is calculated based on the distances from the second position control member to the bridge center of the spectacle frame and to each lens optical center on the spectacle frame.

Abstract: An eyeglasses frame tracing device used in an eyeglasses lens grinding machine. The eyeglasses frame tracing device of the invention comprises a horizontally movable base portion, a rotary base rotatably supported on the base portion, a shaft including a measuring element at its upper end, the shaft being retained on the rotary base so as to relatively move in the vertical and lateral direction with respect to the rotary base, a light-shielding plate which moves in association with the vertical movement and lateral movement of the measuring element shaft and which has openings to allow a part of light to pass therethrough, and a pair of a light emitting section and a light receiving section which are provided opposite to each other with the light-shielding plate interposed therebetween and which moves integrally with the rotary base.

Abstract: A device for tracing a surface such as one defining the lens opening of an eyeglass frame includes a tracer element moved automatically about a rotational axis surrounded by the traced surface and arranged perpendicularly to the area enclosed by the surface. As this rotation occurs a carrier for the tracer element is moved along a second axis extending perpendicularly to the rotational axis in response to a position error signal developed by the tracer element to maintain the position error signal at a substantially zero value through the use of feedback circuitry. The positions of the carrier about the rotational axis and along the second axis are repeatedly captured during the tracing movement to provide point data defining the shape of the traced surface. Results are a smooth steady movement of the tracer element along the surface with a minimum amount of force being exerted on the traced surface by the tracer element.

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: 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: An eyeglasses measuring system comprises a fixed light source which projects a light beam onto two reflecting mirrors. The reflecting mirrors split the light beam into two separate light beams. One of the beams is positioned so that it tangentially illuminates the patient's cornea. A target mirror is then moved, by turning an adjustment screw. This adjustment positions the projection path of the second light beam tangentially onto the front surface of the patient's eyeglasses. The distance between the two beams of light is then determined by reading a scale.

Abstract: The apparatus has a support portion and a holder portion. The support portion includes a stick with two ends. A bifocal segment is coupled to one end of the stick. The holder portion has side walls that clamp onto the eye wire of an eyeglass frame. The holder portion also has arms that clamp the stick to the holder portion. The arms allow the stick and the bifocal segment to move up and down. An eyeglass wearer can install the holder portion onto one of the lower eye wires of the frame, don the frame, and adjust the position of the bifocal segment to a satisfactory position. The bifocal segment position is then measured with the stick. The measurement is used to manufacture the corrective lenses for the frame.

Abstract: A spectacle lens right/left determination apparatus used in an optical characteristic measurement apparatus for checking and measuring optical characteristic of spectacle lenses, comprises a contact plate which has contact surfaces which are brought into contact with an eye-rim of one spectacle lens to be measured and an eye-rim of the other spectacle lens not to be measured when the spectacle lens to be measured, whose central portion is mounted on and fixed to the optical characteristic measurement apparatus, is inserted in a measurement optical path of the optical characteristic measurement apparatus; a first strain sensor, fixed to the contact plate, for, when a left-eye lens is present on the measurement optical path and the eye-rim of a right-eye lens is brought into contact with the contact surface, detecting a strain of the contact plate; a second strain sensor, fixed to the contact plate, for, when the right-eye lens is present on the measurement optical path and the eye-rim of the left-eye lens is b

Abstract: A device for reading contours, as of eyeglass frames, comprises a feeler adapted to be applied to an article in order to read its contour. A carriage supports the feeler and is movable to-and-fro on a guide. A drive motor moves the carriage on the guide. A floating mounting is disposed between the feeler and the drive motor.

Abstract: In an apparatus for measuring a configuration of each of a pair of lens frames (4a, 4b) of a spectacle framework (3), a measuring element (230) is arranged for horizontal and vertical movement relative to the lens frames fixedly held by a holding device (100). The measuring element is movable angularly about an optional reference point (O) within one of the lens frames, along an inner periphery of the lens frame, while causing the measuring element to be in contact with the inner periphery of the lens frame. A first detector unit (224) detects horizontal straight displacement (r) of the measuring element from the reference point. A second detector unit (233) detects vertical straight displacement (z) of the measuring element from the reference point. A third detector unit (209) detects an angle (.theta.) of the angular movement of the measuring element about the reference point.

Abstract: An instrument for use in optical laboratories for indicating the setting of a lens edger device based upon the relationship between a lens pattern or dummy lens and the lens opening of a spectacle frame into which a finished lens is to fit. The instrument can be used to determine the lens edger setting to produce a finished lens to fit both rimmed spectacle frames and rimless spectacle frames. The instrument gauges the size of the spectacle frame lens opening in relationship to either the lens pattern in the event of fitting a lens to rimmed spectacle frames, or a dummy lens in the event of fitting a lens to rimless spectacle frames.

Abstract: Since a certain relationship exists between a pupillary distance at a viewing distance and a pupillary distance to another viewing distance, the pupillary distance at a desired viewing distance can be obtained by making a predetermined correction in the results of a pupillary distance measurement at a fixed viewing distance, without requiring a convexed lens in the device to be moved. The fixed viewing distance is preferably set at a small value such as 1 to 2 meters so that problems such as failure in forming a fused image due to machine near sightedness can be avoided. The device has a sighting mark forming device which can be installed at any portion of the measuring device for enabling easy assembly, unlike conventional measuring devices which require that the sighting mark forming device is located in relation to the (corneal) vertex distance of the subject.

Abstract: Described is a device for testing for a perfect fit of spectacle frames on the head of the spectacle wearer. The device has at least one plate- or blade-shaped force or pressure sensor, which is mounted on a holder and can be applied to the respective contact surfaces between the frame and head. With this device it is possible to make precise measurements of the forces and pressures actually occurring at each individual point so that they can be reproduced, for example, by raising the frame slightly, introducing the pressure sensor to the pertinent point of contact, and lowering the frame down again. Becausede of the negligible structural height of the pressure sensor, the individual contact areas between the frame and head can be tested without having to make any change in the controlled vane position in space existing when the spectacles are worn in place.

Abstract: A spectacle-frame shape data producing method in which a spline interpolation function is used to digitize the shape M of a spectacle frame to provide spectacle-frame shape data, and the shape M of the spectacle frame is obtained by a lens maker's factory to produce spectacle lenses having prescribed values and an optimum thickness conforming to the spectacle frame.

Abstract: A blank having a rectangular shaped body from which a lens pattern is cut to the desired size and shape of a frame lens opening is connected to other identical blanks to form a chain for continuous feeding to a lens pattern generator. The blanks have ball and socket hinge members symmetrically arranged on each edge with a ball hinge member on one edge being opposite a socket hinge member on the other edge. The hinge members are offset with respect to a plane passing through the center of the body between the top and bottom faces of the blank so that the pivot axis of the ball and socket hinge members on one edge is in the plane of the top face and the pivot axis of the ball and socket hinge members on the other edge is in the plane of the bottom face. The blanks are connected together in a like edge-to-like edge fashion and indicia provided to identify the nasal side of the blank alternates from side to side when the blanks are interconnected in a chain.

Abstract: An instrument for measuring the interpupillary distance of a subject is described which comprises two parallel sighting tubes disposed in adjustable spaced relationship along parallel optical axes and interconnected for measuring the spacing between the axes, two eyepiece lenses of preselected equal focal length disposed at corresponding first ends of the sighting tubes, first and second translucent targets bearing recognizable indicia disposed along respective sighting tubes a distance from the lenses equal to the focal length, and an aperture near each lens for limiting the size of the field of view along each optical axis.