摘要:
A method of manufacturing complex optical surfaces in soft contact lenses includes a first step of defining the complex optical surfaces with a computer assisted drafting program using a mix of patient determined parameters and selected manufacturing process determined parameters to define a mathematical "meta lens". A machine code data set is then generated to machine a plurality of contact lens mold inserts to define a complex optical surface on each of the inserts. The machining step is conducted with a single point diamond lathe having submicron precision and repeatability. A first and second plurality of intermediate contact lens mold halves are then molded with said contact lens mold inserts to define said complex optical surfaces on said mold halves having micron range transitions between optical surfaces. The complex geometric forms and optical surfaces include bifocal lenses, aspheric lenses, and toric lenses wherein the lenses may include parabolic or elliptical geometry. The first plurality of mold halves is assembled with the second plurality of mold halves with a polymerizable monomer therebetween and polymerized to form a plurality of soft contact lenses having said complex optical surfaces defined thereon.
摘要:
An apparatus for molding polystyrene mold halves which are used, for subsequent molding of a soft contact lens. The apparatus is designed with superior heat conduction capacity so as to minimize the molding cycle time, while simultaneously producing uniformly precise and accurate optical quality surfaces. Molten polystyrene is provided via a hot runner system to a plurality of mold cavities. In a specific variation, the convex surface provides the optical quality surface to the concave surface of the mold half produced thereby. The structural element which defines the convex surface includes a hollow cylindrical bushing and a removable power insert mounted therein, which may be changed so that the prescription strength of the contact lens to be formed by the mold may be varied. In a first embodiment, the power insert includes only a convex surface at its operational end. In a second embodiment, the power insert includes an annular flat surface surrounding the convex surface, defining at the junction therebetween a discontinuity of curvature, which imparts a sharp edge to the mold half formed thereby. The power insert may be constructed of pure steel, or alternatively, it may be made of brass, copper chromium, or cobalt-nickel alloyed martensitic steel. The power insert may be coated with a surface layer of nickel phosphor or silicone oxide, or chrome nitride. These layers may be turned to their proper thicknesses and dimensions by diamond cutters, and they may be thermally hardened.
摘要:
A method and apparatus for the manufacture of lens molds used in the formation of optical contact lenses, the apparatus including a center gate aligned on the central axis of the lens mold cavity for delivery of the melt polymer in an axisymmetrical manner. The methodology produces lens molds of extremely precise dimensions as measured against lens molds produced with side gated technology.
摘要:
A packaging arrangement for the containment in a blister package of at least one hydrophilic contact lens in a sterile aqueous solution. Provision is made for incorporating support structure in the form of stiffening groove or wall elements in flanges of base members of the blister packages to facilitate an improved attachment between the base members of the blister packages housing the contact lenses, and a flexible cover sheet utilized for sealing engagement with the base members while incorporating additional strength to the blister package structures.
摘要:
A base member for a blister package for the containment of a contact lens includes a planar flange extending outwardly about a cavity for housing the contact lens. Proximate the peripheral edge of the flange, there is formed a continuous groove into which there is pressed the material of a flexible cover sheet of the blister package so as to clampingly engage the base member.
摘要:
A base member for a blister package for the containment of a contact lens includes a planar flange extending outwardly about a cavity for housing the contact lens. Proximate the peripheral edge of the flange, there is formed a continuous groove into which there is pressed the material of a flexible cover sheet of the blister package so as to clampingly engage the base member.
摘要:
An arrangement for molding a front or back polystyrene mold half which is used, with a second complementary back or front mold half, for subsequent molding of a soft contact lens such as a hydrogel soft contact lens. Each mold half defines a convex curved surface and a concave curved surface spaced therefrom, with one of the surfaces defining an optical quality curved surface for the soft contact lens. A heated molding machine introduces molten polystyrene through a hot runner system to a plurality of mold cavities, each of which defines an optical quality curved surface and also a second noncritical surface. The optical quality surface of the mold cavity is positioned further away from the heated hot runner side of the mold than the second surface, which allows faster cooling of the optical quality surface of the mold cavity. Each mold cavity has a first insert on the optical quality side of the mold cavity and a second insert on the second side. Each of the first and second inserts has a circumferential cooling passageway defined therearound or in proximity for the first inserts, and also includes a bubbler positioned internally therein. Coolant is circulated in a turbulent mode through the circumferential passageways and also through the bubblers against inner surfaces of the insert to provide rapid cooling of the mold cavity.
摘要:
Disclosed are mold halves useful in molding a contact lens by polymerization of a polymerizable composition disposed between the mold halves. The mold halves are of rigid thermoplastic, preferably polystyrene, transparent to ultraviolet light.
摘要:
A composite or secondary packaging arrangement for the containment of hydrophilic contact lenses in a sterile aqueous solution. More specifically disclosed is a composite or secondary packaging arrangement wherein pluralities of disposable hydrophilic contact lenses possessing different optical characteristics or prescriptions are contained in one or more specific packaging arrays which are then collectively housed in separate paired box-like compartments or carton structures in a preselected customized manner so as to provide specified or essentially measured supplies of differing contact lenses for prescribed use in both eyes of a consumer over a predetermined period of time.
摘要:
This invention provides a mold comprising a first mold half which works in conjunction with a second mold half for forming ophthalmic devices wherein said first mold half comprises at least one changeable cassette comprising inserts for forming said ophthalmic devices. The mold is particularly well-suited for use in an injection molding machine.