Abstract: A method and lens are disclosed for improving the visual comfort and perceived vision of a person viewing an image transmitted from a video display terminal. The use of a lens tint complementary to the image color on the terminal screen is employed to improve screen contrast and reduce fatigue.

Abstract: In the embodiments of the bipolar progressive power ophthalmic lens described in the specification, the constant power distance portion and reading portion regions of the progressive power surface are reduced to mathemtical points and the surface astigmatism aberration is reduced to a minimum level by spreading it over a maximally large area of the lens. The points are the poles of a bipolar system of isopower contours and the entire progressive surface is swept out by the curve of intersection formed between a sphere of variable radius and a corresponding circular cylinder of variable diameter with the dimensions of relative positions of intersecting sphere and cylinder chosen so as to produce a gently curving surface to provide a smooth optical effect.

Abstract: A transparent faceshield for protecting the face and eyes from impact and the like is detachably connected to an arcuate visor or crown using detents integrally molded to the crown and corresponding through-holes in the faceshield which receive and engage the detents. The use of integrally molded detents permits removable attachment of the faceshield to the crown without the necessity for secondary operations or discrete assembly hardware thus providing a system which is easily assembled and disassembled by the end user.

Abstract: A spectacle assembly kit with a lockable custom fitting nosepiece is disclosed wherein a wearer is able to select an appropriately sized nosepiece, manually attach it to the spectacle frame without tools, check for correct fit, then lock the nosepiece in place permanently. Also disclosed is an alternative nosepiece attachment wherein the nosepiece is manually attached and locked to the frame in one step.

Abstract: Disclosed is a hinge assembly for an eyeglass frame which comprises a male hinge member to which a female hinge member is pivotally interconnected. The female hinge member includes a pair of parallel hinge leaves which are joined by a connecting wall in the outer side of the female hinge member. Each hinge leaf includes a pin-receiving slot perpendicular to the longitudinal axis of the female hinge member and a ramp leading to the slot. A raised surface positioned between each ramp and the connecting wall helps guide a pin along the ramp. The male hinge member includes a hinge ear with a pin extending above and below it. The male hinge member and the female hinge member are brought together by inserting the hinge ear between the hinge leaves, with the pin aligned against the side of the raised surfaces as a guide, and forcing the members together so that the pin travels along the ramps until it is engaged by the pin-receiving slots.

Abstract: A universal fit protective spectacle and assembly kit therefor are disclosed. The protective spectacle is especially adapted for use by eyeglass wearers since it includes an inner spectacle that holds corrective lenses removably mounted to an outer protective spectacle. The protective spectacle also includes removably mountale and interchangable nosepieces of various sizes to achieve a comfortable fit.

Abstract: An organic photochromic composition comprising spiro [indoline-2,3'-[3H]-naphth [2,1-b] [1,4] oxazine] dye (spirooxazine dye) and unconventional ultraviolet stabilizers. The ultraviolet stabilizers improve the light fatigue resistance of the spirooxazine (S.O.) dye and will not hinder the photocolorability of the photochromic composition. The unconventional ultraviolet stabilizers belong to the class of hindered amine light stabilizers (HALS) and excited state quenchers.

Abstract: An optical lens carrying support structure for use with a protective face mask, comprising a pair of lens frames, each frame comprising an eyewire and a hinge portion, the lens frames being connected by a hinged nosepiece. The support structure attaches to the face mask by a slideably releasable dove-tail connection to a trapezoidal back-block, which back-block rigidly attaches to the face mask, with two opposite faces of the trapezoidal back-block inclined with respect to each other so as to establish the proper pantoscopic angle. The face-form angle is accomplished by virtue of an angled relation of the eyewire to the hinge portion of the lens frame. The lens frames fold back toward each other, facilitating removal of the lenses and folding the face mask assembly flat.

Abstract: A system for attaching a replaceable, customizable nosepiece to an eyeglass frame is disclosed where the eyeglass and nosepiece fit together through a snappable attachment. The eyewires of the eyeglass frame are provided with a notch and adjacent projection. The nosepiece is roughly horseshoe shape, sized and shaped to fit between the eyewires under the connecting bridge of the frame. The tips of the horseshoe are shaped to snap into the notches on the eyewires, and be retained by the adjacent projections. In this manner, the nosepiece may be specifically selected for or customized to the particular size and shape of the user's nose.

Abstract: Disclosed is an eyeglass frame and method of assembling the same in which a temple includes a pair of parallel ears which extend from one end of the temple. Each ear includes a pin receiving hole, and on the facing surfaces of the ears, a ramped slot extends from the hole to one of the side surfaces. The depth of the slot increases as it approaches the side surface. The lens supporting structure includes a single extension member with a pin supporting hole. The pin is inserted into this hole, and the lens supporting structure and temple are brought together so that the two ends of the pin are aligned with the two slots on the temple. As the temple and the lens supporting structure are urged toward one another, the ears of the temple are forced apart by the ends of the pin until the pin reaches the pin receiving hole at which point the ends fall into the hole.

Abstract: The organic photochromic composition of this invention comprises trifluoromethyl substituted spiro (indoline-2,3'-(3H) napth-(2,1-b)(1,4)oxazine) (SO) dyes. This new class of (SO) photochromic compounds has a more neutral color when subjected to ultraviolet light irradiation.When used with a photochromic plastic embodiment, these (SO) compounds give the plastic embodiment a high luminous transmittance in an unactivated state, which can be darkened significantly when subjected to ultraviolet light irradiation. When an ultraviolet stabilizer is used with the photochromic compositions of this invention, the light fatigue resistance of the (SO) dye is improved and it will not hinder the photocolorability of the photochromic composition.

Abstract: Organic polymeric plastic substrates of optical elements are made anti-static and abrasion-resistant by: applying a conductive layer to at least one surface of the plastic substrate; and overcoating the conductive layer with an abrasion-resistant layer.

Abstract: A multiple ply, fold-flat, disposable respirator having, as one ply, a layer of a toxic gas or vapor absorbing material. Another ply is an aerosol filter. The respirator has an inturned vertical seam covered with a strip of foamed elastomer.

Abstract: This invention relates to a dual reusable filter respirator system. The respirator can be worn in dust, mist and fume environments for very long periods of time, while providing increased visibility, safety and comfort for the respirator wearer. A significant feature of the respirator is a pair of triangular shaped filter housings which allow the area of the filter media to be increased while at the same time reducing filter housing obstructions to the vision of the respirator wearer and creating a greater overall compactness of design.

Abstract: An apparatus and method for molding polycarbonate lenses is disclosed in which the lenses are formed in a single injection molding operation. Polycarbonate is injected into a cavity between two movable dies which are forced apart by the injected polycarbonate. These dies are then urged together forcing a portion of the injected polycarbonate back through the same port through which the polycarbonate was injected. The finished lens does not have the knit line normally associated with injection molded lenses.

Abstract: Visual indication of respirator cartridge end-of-service life is accomplished with color indicator means particularly designed for long term shelf life and an adaptability to respond to both water soluble and water insoluble organic vapors.

Abstract: An ophthalmic lens for the correction of presbyopia having a progressive power surface generated by the line of intersection of an ordered sequence of intersecting spheres and cylinder surfaces, the cylinder surfaces being so chosen as to produce a uniform distribution of aberration and optical power for gently curving smooth optical effect.

Abstract: A dead stop for workpiece positioning in collet chucking machinery. A fixed length stop is provided within a machine collet for establishing workpiece position independently of the collet clamping function and workpiece diameter.

Abstract: Novel anti-static and/or anti-reflective optical elements are produced by coating at least one surface of an organic polymeric plastic substrate with a protective organo-silica coating composition and then subjecting the coated plastic substrate to a glow discharge treatment.