Abstract: A head-mounted fixing device includes: a head frame including two side frame portions, and a front frame portion located between the two side frame portions and connected to the two side frame portions, and the two side frame portions and the front frame portion being made of rigid materials; an elastic piece including one end connected to the front frame portion; a headgear including an arc portion and a top portion, wherein two ends of the arc portion are respectively connected to the two side frame portions, one end of the top portion is connected to another end of the elastic piece, and another end of the top portion is connected to the arc portion; it is characterized in that the front frame portion is used to abut against a user's forehead to provide a fulcrum.

Abstract: A binocular device that is wearable on the head of the user or wearer and does not require any hands to hold in place. The device has a pair of telescope sections that transmit an image to an eyepiece viewable by a wearer. Each eyepiece can be adjusted laterally to conform to the wearer's interpupillary distance; vertically, preferably vertically in an arc to provide a desired viewing angle; and longitudinally in relation to the wearer's eyes to a desired eye relief; the adjustments providing a custom-fit device.

Abstract: The invention discloses a head-mounted display apparatus. The head-mounted display comprises a headband module and a head-mounted display module, wherein the head-mounted display comprises an optical module, the headband comprises a connecting structure connected with the head-mounted display housing so as to adjust the wearing angle of the head-mounted display module; The optical module comprises a module housing, a left lens barrel mechanism, a right lens barrel mechanism, a left sight distance adjusting mechanism and a left pupillary distance adjusting mechanism for adjusting the sight distance and pupillary distance of the left lens barrel mechanism, a right sight distance adjusting mechanism and a right pupillary distance adjusting mechanism for adjusting the sight distance and pupillary distance of the right lens barrel mechanism. The head-mounted display can separately adjust the sight distance and pupillary distance of the left and right lens barrel mechanism, as well as the wearing angle.

Abstract: Disclosed is an electronic device. An electronic device according to the present invention includes: a main frame having a first opening; a display unit connected to the main frame and having a display area which may be exposed through the first opening; and a virtual reality frame movably coupled to the main frame and having a second opening to which a first lens is coupled, in which when the virtual reality frame moves to a first location where the first opening and the second opening are arranged side by side in a sight direction of a user, the user is capable of recognizing an image of the display unit as a virtual reality image through the first lens, and when the virtual reality frame moves to a second location deviated from the first location, the user is capable of recognizing the image of the display unit as an augmented reality image.

Abstract: Helmet mounts for mounting an associated viewing device on a helmet, includes a first pivoting segment for attachment to the helmet and a second pivoting segment for attachment to the associated viewing device. The second pivoting segment is pivotable relative to the first pivoting segment for selectively supporting the associated viewing device in a first, operational position before the eyes of a user donning the helmet and a second, stowed position above a line of sight of a viewer donning the helmet. In one aspect, the first pivoting segment includes a vertical adjust mechanism having a base plate, a pair of guide rails attached to the base plate and defining a channel therebetween, a sliding plate slidably attached to the guide rails, and a clamping mechanism for selectively applying a clamping force to secure the sliding plate at a desired position relative to the base plate.

Abstract: A helmet that can include a helmet body comprising an energy absorption layer and an outer shell. A first opening can be formed through the outer shell and extend into the energy absorbing layer, the first opening including a perimeter. A first sleeve can be disposed at least partially within the first opening, the first sleeve including a first end including a first flange coupled to the outer shell and extending beyond the perimeter of the first opening, and a second end opposite the first end including a base disposed over the energy absorption layer. A camera can be coupled to the first sleeve and exposed through the first opening. The helmet can further include the first sleeve including a depth greater than a width or a length. The first flange can be directly coupled to an outer surface or an inner of the outer shell.

Abstract: A removable optical loupe that is mountable to headwear is provided. The inventive loupe is configured to clip on to the brim of a hat, or the bill of a cap or visor. Embodiments of the inventive loupe have a pivoting joint for positioning the lens of the optical loupe into and out of the line of sight when not in use. The lens of the inventive optical loupe is used for magnifying objects for inspection.

Abstract: An apparatus of the present disclosure enhances the audio/visual experience of a portable digital device, and comprises a lens positioning slot, a lens storage compartment, a passive audio amplifier, a receiving station.

Abstract: A comfortable finger mounted optical device requiring an optical device, at least one bonding holder, strap, or elastic band sized to receive any finger(s) or thumb, and a base plate or case. The comfortable finger mounted optical device can have many different variations including, but not limited to, the incorporation of split rings, straps, elastic bands, sleeves, Fresnel lens, or pivotal or slidable lens assemblies. In addition, the comfortable finger mounted optical device can have various attachments including, but not limited to, advertisements, an elastic cover, or LED's. This device is useable, convenient, as well as comfortable and snug-fitting.

Abstract: A personal media viewing device has a frame that adjustably holds a pair of lenses. The frame has tracks along a bottom inside portion that guides the lenses as a lens adjustment knob is turned. The adjustment knob is attached to a translating screw shaft that has opposingly threaded portions that interact with a left and right traveling nut attached to each lens and moves each lens in an opposite direction. An elastic strap is used to removably hold a personal media device to the frame and a head attachment portion is provided to allow a user to operate the personal media viewing device hands free. The adjustment knob allows a user to adjust the lenses to an off-axis position selected to reduce eyestrain, headaches and other non-desirable effects associated with viewing a device in front of the user's eyes.

Abstract: A lens barrel and imaging device with a low likelihood of optical characteristics being degraded by an impact from a fall or the like may be provided. A lens barrel including: a retention member that retains an optical system; and a first guide shaft that guides the retention member to be movable along an optical axis of the optical system, wherein the retention member includes, a first engaging portion that engages with the first guide shaft, and an abutting portion disposed at the opposite side of the optical axis from the side thereof at which the first engaging portion is disposed, at a position that is offset in the optical axis direction from the engaging portion, the abutting portion being abuttable against an abutted portion when a force in the optical axis direction is applied at least to the retention member.

Abstract: A system tube of an endoscope optical system, designed to contain cylindrical elements of an image guide provided with lenses and to support the elements by tongues cut out of the wall of the system tube and deformed nonelastically. Wherein the tongues are deformed toward the outside and are bent elastically by a holder toward the inside to below the level of the outer surface of the system tube. In a system tube of an endoscope optical system, designed to contain cylindrical elements of an image guide provided with lenses and to support the elements by means of nonelastically deformed tongues cut out of the wall of the system tube, the tongues are deformed toward the outside and are elastically bent by a holder toward the inside to below the level of the outer surface of the system tube.

Abstract: An optical element unit is provided comprising an optical element group for projecting light along an optical axis of the optical element group and a housing having an inner housing part partly defining a first space and a light passageway between the inner housing part and a second space. The inner housing part receives the optical element group. The optical element group comprises an ultimate optical element located in the region of the light passageway. A load-relieving device is provided adjacent to the ultimate optical element, the load relieving device partly defining the first space and the second space and at least partly relieving the ultimate optical element from loads resulting from pressure differences between the first space.

Abstract: A method of manufacturing suspension devices comprising the steps of: a) forming an integral elastic sheet, the elastic sheet having first and second suspension devices, each suspension device being provided with attachment parts configured to be fixed to a movable object, fixing parts configured to be fixed to a base, and elastic parts connected between the attachment parts and the fixing parts respectively and configured to bias the object relative to the base, the elastic parts of the suspension devices being alternately distributed; b) separating the first and second suspension devices from each other before being attached to the object.

Abstract: A lens assembly for securing in an opening in a face plate of a face protector has a first, retainer lens of shape and dimensions configured to be secured in the front opening of a face plate and having a curvature substantially matching the curvature of the face plate. A second lens of smaller dimensions is secured behind the first lens to provide a lens-in-a-lens configuration. The lens assembly may be releasably secured in the face plate opening and the second lens is interchangeable with sets of lenses having different properties such as lens shade. The retainer assembly has a back cover and a gasket or spacer between the back cover and second lens to allow second lenses of different depths to be secured in the assembly.

Abstract: A survival apparatus operable to ignite a combustible material wherein the survival apparatus additionally functions as a zipper pull-tab for an article of clothing. The survival apparatus further includes a body that is substantially rigid and generally rectangular in shape. The body includes a first aperture that is oval in shape and has a convex lens mounted therein. A coating is disposed over the body operable to substantially inhibit damage to the lens mounted within the first aperture during use as a zipper pull. A release strip is intermediate the body and the coating wherein the release strip further includes a tab providing an interface to engage the release strip.

Abstract: A voice coil motor includes a movable member, a base, and a first elastic member. The movable member comprises a barrel, and a plurality of fixing posts protrudes from the bottom of the barrel. The base defines a through hole, a plurality of recessed portions, and a plurality of concavities. The axis of through hole is coaxial with the barrel. The recessed portions surround the aperture. Each of the recessed portions is arranged between two concavities. The depth of the recessed portion is less than the height of the fixing post, and the depth of the concavity is larger than that of the recessed portion. The elastic member comprises an elastic portion, which defines a first fixing hole. The fixing post extends through the first fixing hole and is received in the recessed portion.

Abstract: A lens barrel unit includes a holder configured to hold a lens, a cam cylinder including a cam groove configured to engage with the holder and define a movement of the holder in an optical axis direction, and a projection that has a part of the cam groove and projects in the optical axis direction, and a straightforward movement cylinder configured to guide a straightforward movement of the holder, the straightforward movement cylinder including a flange forming a notch. In a process from a retraction state in which the projection is located in the notch to an image pickup state in which the projection is located outside of the notch, the straightforward movement cylinder moves relative to the cam cylinder in the optical axis direction.

Abstract: A collapsible lens barrel is provided, including a mechanism capable of reliably inhibiting rotation of a rotational barrel even if any impact is applied thereto, for example, due to a fall with the barrel being extended. When the rotational barrel is pressed upon a fixed member due to impact in defiance of the biasing force of a wave spring, a first engagement portion provided at a camera body-side end of the rotational barrel engages with second engagement portions provided on a subject-side surface of the fixed member, which locks rotation of the rotational barrel, thereby making it possible to prevent gears from being damaged, for example.

Abstract: A housing structure has a frame structure 1 on which there are arranged via connecting elements 7 several optical elements 5 which are held in mounts 6 or structural modules 6?. The optical elements 5 are detachably connected to the frame structure 1 with their mounts 6 or structural modules 6? and connecting elements 7 in such a way that in the installed state they are integrated as bearing units in the frame structure 1.

Abstract: A lens assembly for securing in an opening in a face plate of a face protector has a first, retainer lens of shape and dimensions configured to be secured in the front opening of a face plate and having a curvature substantially matching the curvature of the face plate. A second lens of smaller dimensions is secured behind the first lens to provide a lens-in-a-lens configuration. The lens assembly may be releasably secured in the face plate opening and the second lens is interchangeable with sets of lenses having different properties such as lens shade. The retainer assembly has a back cover and a gasket or spacer between the back cover and second lens to allow second lenses of different depths to be secured in the assembly.

Abstract: A lens module includes a barrel, a first lens, an annular retaining member and three driving devices. The retaining member is arranged in the barrel. The driving devices are arranged on the retaining member. Each of the driving devices has a base attached on the retaining member, a plurality of first electrodes formed on the base and a comb-shaped carrier. The carrier has a beam attached on the base and a plurality of second electrodes extending from the beam and suspended above the first electrodes at a first position. The first lens is carried by the second electrodes. When a first voltage is applied on the first electrodes and a second voltage is applied on the second electrodes, an electrostatic force is generated between the first electrodes and the second electrodes, and the second electrodes are moved down, such that the first lens is brought to a second position.

Abstract: An optical element unit is provided comprising an optical element group for projecting light along an optical axis of the optical element group and a housing having an inner housing part partly defining a first space and a light passageway between the inner housing part and a second space. The inner housing part receives the optical element group. The optical element group comprises an ultimate optical element located in the region of the light passageway. A load-relieving device is provided adjacent to the ultimate optical element, the load relieving device partly defining the first space and the second space and at least partly relieving the ultimate optical element from loads resulting from pressure differences between the first space.

Abstract: A lens module includes a base, a carrier carrying a lens, two elastic members attached on the base and supporting the carrier, and a number of thermal actuators. The carrier is movable relative to the base. The thermal actuators each have a first arm and a second arm. The first and second arms are aligned in an optical axis direction of the lens and each have a first end electrically and mechanically coupled to the base and a distal end, the distal ends thereof are interconnected and attached to the carrier. The first arms are thinner than the second arms so that the first arms are capable of deflecting toward the second arms due to differential heat generated when an electrical current is passed through the first and second arms from the first ends thereof to the second ends thereof, thereby the carrier is moved.

Abstract: The invention relates to an ophthalmological display comprising an optical imager (10) for shaping light beams emitted by a miniature screen (20) of a light beam generator system and for directing the beams towards the eye (O) of the wearer to enable an image (I) to be viewed, said imager presenting an outlet optical axis (A). According to the invention, the display includes a device for adjusting to the user's pupil spacing, the device including means for adjusting the position of said image (I1, I2) in a plane substantially perpendicular to said optical axis (A).

Abstract: Various ways are provided to visually distinguish one pair of TV 3D glasses from another in a home, including numbering the glasses, providing a white space on each pair of glasses that can be marked, color coding the glasses, and providing a visually unique band for each pair of glasses that can be engaged with the stem of the glasses.

Abstract: A lens support system for stabilizing and securing a large camera lens when it is attached to a camera is disclosed. The lens support system consists of a lens cradle that is attached to the tripod mount of a large camera lens, and a neck strap attached to the lens cradle that will be worn around the photographer's neck. The lens support system can also be used to secure a lens when unattached to a camera, and can be used as a balanced hand-hold without the neck strap.

Abstract: A mechanism for adjusting the angular position of an optical device with respect to a field helmet is disclosed. The mechanism includes an optical device mounting component for coupling to the optical device. A field helmet mounting component is provided for coupling to the field helmet. The field helmet mounting component is rotatably coupled to the optical device mounting component about an axis of rotation. An angular adjustment mechanism is engaged between the optical device mounting component and the field helmet mounting component. The angular adjustment mechanism includes a translating member that is moveably translatable along an axis of translation for engaging a surface of either the field helmet mounting component or the optical device mounting component. Translation of the translating member along the axis of translation induces rotation of the optical device mounting component about the axis of rotation for adjusting the angular position of the optical device.

Abstract: An optical assembly includes a light path and at least one optic to be positioned in the path. A support arrangement supports the optic having a foot arrangement including at least one foot that receives a direct manipulation with the foot slidingly engaged against a support surface to move the optic relative to the light path. Movement of the foot may move the optic along a predetermined path. The foot defines a footprint for engaging the support surface and receives the direct manipulation in a way which changes the footprint on the support surface to move the optic responsive to changes in the footprint. A movement arrangement may selectively bias the foot against the support surface during a movement mode, intended to permit movement of the foot against the support surface, and in a locked mode, intended to lock the foot against the support surface.

Abstract: A mechanism for adjusting the position of an optical device with respect to a field helmet along an axis of translation is provided. The mechanism comprises an optical device mounting component for coupling to the optical device. A field helmet mounting component for coupling to the field helmet is slideably coupled to the optical device mounting component along the axis of translation. A lever configured for selectively engaging a surface of either mounting component permits translation of the optical device mounting component along the axis of translation with respect to the field helmet. The optical device mounting component is configured to translate along the axis of translation with respect to the field helmet between an extended position and a retracted position, wherein the optical device is proximal to the helmet in the retracted position and distal to the helmet in the extended position.

Abstract: A mounting process/device for mounting and alignment of micro optical electro-mechanical systems (MOEMS) elements and/or devices. The mounting process/device can be obtained by attaching at least one optical element onto a mounting system, which contains an embedded optical element. The attached optical element(s) are aligned with respect to the embedded optical element.

Abstract: A lens barrel comprising: a plurality of lens groups including two lens groups for guiding object light; and a lens drive apparatus for moving the two lens groups in the plurality of lens groups in a direction of an optical axis, the lens drive apparatus includes a single motor and a lead screw rotated by the rotation of the motor; wherein the lens drive apparatus is structured in such a manner that one lens group of the two lens groups is moved linearly to the rotation of the lead screw, and the other lens group of the two lens groups is moved non-linearly to the rotation of the lead screw.

Abstract: A device is shown having at least two movable lens units, wherein each of the at least two movable lens units has at least one lens, wherein the at least two movable lens units are movable into a first state wherein the at least two movable lens units are arranged in parallel to each other, and wherein the at least two movable lens units are movable into a second state wherein the at least two movable lens units are arranged on top of each other for positioning the lenses of the at least two movable lens units in an optical axis.

Abstract: A magnetically activated switch assembly is provided. The magnetically activated switch assembly includes a magnet and a magnetic circuit. The magnetic circuit includes a magnetically activated switch, a first set of flux conductors, and a second set of flux conductors. The first set of flux conductors has first flux conductor flanges adapted to conduct flux from ends of the magnet. The second set of flux conductors is slidingly positioned relative to the first set of flux conductors and is adapted to conduct flux from the first set of flux conductors to the magnetically activated switch. The first set of flux conductors are adapted to rotate clockwise or counter-clockwise and to tilt up or down. The first magnetic circuit is adapted to conduct flux to activate the magnetically activated switch only when the first flux conductor flanges are rotationally aligned with ends of the magnet and tilted to an operational position.

Abstract: A mechanism for permitting selective adjustment of the angular position of a head-mounted night vision device is provided. The mechanism comprises a housing positioned adjacent the night vision device. A shaft defining a longitudinal axis is at least partially positioned within or adjacent the housing. The shaft is rotatively coupled to the night vision device, wherein rotation of the shaft induces rotation of the night vision device. A moveable lever is coupled to the shaft for rotating the shaft. Means for selectively limiting rotation of the shaft are provided, wherein the means are moveable between a first position and a second position. In the first position the means permit rotation of the shaft and the optical device, and in the second position the means limit rotation of the shaft and the optical device.

Abstract: An optical element mounting includes a frame, and a shuttle that is translatable relative to the frame. The shuttle includes inner and outer portions that are mechanically coupled together by a plurality of flexures that effectively bending and twisting of the shuttle from being transmitted to an optical element, such as an optical window, that is mounted on the inner portion of the shuttle. The flexures may be thin linking strips of material between the outer and inner portions. The flexures may have a thickness that is greater in an expected load direction, than in a direction perpendicular to the load direction. The optical mounting may include a locking mechanism, for example including a shape memory alloy wire, to lock the shuttle in a predetermined location relative to the frame.

Abstract: An operating menu is provided for display with a touch-sensitive display screen (105) in a surgical microscope (100). The operating menu has a first operator-controlled area (106) wherein at least one touch-sensitive actuation field (107) is provided for adjusting a surgical microscope operating mode. In a second operator-controlled area (108) of the operating menu, a touch-sensitive actuation field (109) is provided with a function dependent upon an adjusted surgical microscope operating mode.

Abstract: An optical lens has an inner lens surface and an outer lens surface separated by a lens thickness adjacent to an edge portion of the lens. The edge portion has at least a partially exposed edge surface extending substantially linearly from the inner lens surface toward the outer lens surface coextensively with at least a major portion of the lens thickness at a location adjacent to the edge portion, and at a predetermined inclination with respect to a portion of the lens surface at such location.

Abstract: A suspension apparatus comprises a lens holder, a suspension spring and a supporting base. The supporting base is formed with an opening for accommodating the lens holder. The lens holder is for positioning a lens unit. The suspension spring is manufactured by stamping process to form a long strip with a plurality of suspension springs. The strip is then guided into a mold, and plastic injection molding process is performed in that mold so as to produce the lens holder and supporting base affixed respectively to either end of the suspension spring in one piece. After that, excess material of the strip is cut off. The suspension apparatus as above described is suitable for mass production. In addition, because of the high precision of mold, the inaccuracy of assembly and fabrication is minimized. The volume of the whole apparatus and the cost of production are also vastly decreased.

Abstract: A focusing-free microlens assembly includes a holder and a plurality of optical lenses mounted on the holder. Each of the holder and the optical lenses has a tolerance, and a combinative tolerance of the tolerances of the holder and the optical lenses is less than a depth of focus.

Abstract: A mechanism for adjusting the angular position of an optical device with respect to a field helmet is disclosed. The mechanism includes an optical device mounting component for coupling to the optical device. A field helmet mounting component is provided for coupling to the field helmet. The field helmet mounting component is rotatably coupled to the optical device mounting component about an axis of rotation. An angular adjustment mechanism is engaged between the optical device mounting component and the field helmet mounting component. The angular adjustment mechanism includes a translating member that is moveably translatable along an axis of translation for engaging a surface of either the field helmet mounting component or the optical device mounting component. Translation of the translating member along the axis of translation induces rotation of the optical device mounting component about the axis of rotation for adjusting the angular position of the optical device.

Abstract: A helmet mount for night vision apparatus wherein night vision goggles can be coupled and uncoupled to its power pack without the use of tools and wherein the power pack can be coupled and uncoupled to a helmet without the use of tools. When an aviator wearing a helmet with night vision apparatus so mounted, is ejected from his aircraft both the goggles and the power pack are released from the helmet.

Abstract: A mechanism for adjusting the position of an optical device with respect to a field helmet along an axis of translation is provided. The mechanism comprises an optical device mounting component for coupling to the optical device. A field helmet mounting component for coupling to the field helmet is slideably coupled to the optical device mounting component along the axis of translation. A lever configured for selectively engaging a surface of either mounting component permits translation of the optical device mounting component along the axis of translation with respect to the field helmet. The optical device mounting component is configured to translate along the axis of translation with respect to the field helmet between an extended position and a retracted position, wherein the optical device is proximal to the helmet in the retracted position and distal to the helmet in the extended position.

Abstract: A mechanism for permitting selective adjustment of the angular position of a head-mounted night vision device is provided. The mechanism comprises a housing positioned adjacent the night vision device. A shaft defining a longitudinal axis is at least partially positioned within or adjacent the housing. The shaft is rotatively coupled to the night vision device, wherein rotation of the shaft induces rotation of the night vision device. A moveable lever is coupled to the shaft for rotating the shaft. Means for selectively limiting rotation of the shaft are provided, wherein the means are moveable between a first position and a second position. In the first position the means permit rotation of the shaft and the optical device, and in the second position the means limit rotation of the shaft and the optical device.

Abstract: An optical assembly (16) for a precision apparatus (10) includes an optical element (234) and a housing (230) that defines a housing cavity (244). The housing (230) includes a body section (238), a removable section (240) and a fastener assembly (242). The body section (238) is secured to an apparatus frame (12) of the precision apparatus (10). The removable section (240) retains the optical element (234) with the optical element (234) positioned in the housing cavity (244). The fastener assembly (242) selective secures the removable section (240) to the body section (238). With this design, the removable section (240) can be selectively removed to repair or replace the optical element (234) and the optical element (234) is supported by a rigid mechanical housing (230) so that the optical element (234) is less susceptible to long term or operating misalignments.

Abstract: Objective lens 20 is placed above the bobbin 40 at a position opposite to the light emitting end of the light guiding member, and the fixing portions 31 provided appropriately between the objective lens 20 and the lens support 41 are hardened in a short time because of being exposed to a UV hardening light beam which is selectively irradiated onto the fixing portions, or the intensity of which has been reduced to the wavelength region in which optical characteristics of the objective lens are practically deteriorated, in order to reduce the deterioration in the transmission characteristics in the wavelength range at which the optical elements are to be used, when fixing optical elements such as a plastic objective lens, etc., are used with a UV hardening type of adhesive.

Abstract: An optical assembly includes a light path and at least one optic to be positioned in the path. A support arrangement supports the optic having a foot arrangement including at least one foot that receives a direct manipulation with the foot slidingly engaged against a support surface to move the optic relative to the light path. Movement of the foot may move the optic along a predetermined path. The foot defines a footprint for engaging the support surface and receives the direct manipulation in a way which changes the footprint on the support surface to move the optic responsive to changes in the footprint. A movement arrangement may selectively bias the foot against the support surface during a movement mode, intended to permit movement of the foot against the support surface, and in a locked mode, intended to lock the foot against the support surface.

Abstract: There are provided a lens barrel unit and an imaging apparatus in which a plurality of constituent elements can be driven using a linear driving mechanism.

Abstract: In an objective lens driving device having a lens holder movably holding an objective lens, a damper base, and a suspension member elastically supporting the lens holder with respect to the damper base, the suspension member consists of four suspension wires disposed on both sides of the damper base and the lens holder. The damper base has first supporting portions for supporting one end of each suspension wire while the lens holder has second supporting portions for supporting another end of each suspension wire. The second supporting portions are apart from the first supporting portion by a first distance. The damper base has damper portions which are disposed between the first and the second supporting portions and which are apart from the first supporting portions by a second distance. The second distance is laid in a range between one-fifths and two-fifths of the first distance.

Abstract: An optical lens has an inner lens surface and an outer lens surface separated by a lens thickness adjacent to an edge portion of the lens. The edge portion has at least a partially exposed edge surface extending substantially linearly from the inner lens surface toward the outer lens surface coextensively with at least a major portion of the lens thickness at a location adjacent to the edge portion, and at a predetermined inclination with respect to a portion of the lens surface at such location.