In a method for manufacturing ophthalmic, telescopic, microscopic, etc. lenses, the use of a radiation (e.g., UV or visible light) curable adhesive formulation containing a predominant amount of an acrylic capped organic prepolymer; a lesser amount of an ethylenically unsaturated diluent monomer; a minor amount of a non-reactive releasing agent and a suitable photoinitiator for blocking (bonding) and deblocking (debonding) a lens blank to a support member.

A machine and process for making an ultraviolet cured block for an ophthalmic lens are provided in which a lens is placed at an input port to the machine by an operator. Data related to the lens is fed to or stored in the machine from either a keyboard or a data base. The lens is then collected from the input port for processing and transported, preferably by means of pneumatics, to a block molding point within the confines of the machine. A special adhesive is administered to the surface of a mold unit and the mold unit is then positioned to receive the lens. Pressure is applied to squeeze the lens against the adhesive and the mold. After molding the adhesive onto the lens, the lens and mold are transported via servo slide to a UV station where curing takes place from above the lens. After preliminary curing, the lens and mold unit are taken to a removal station and the lens, together with the adhesive cured to its front surface, is removed from the mold unit, again preferably by means of pneumatics. The separated blocked lens is then transported to a second curing station where it is cured by UV from the underside before being released to the operator. In the final stage of the cycle, a daubing unit is used to apply a releasing agent to the surface of the mold in preparation for the next cycle.

A conformable tape for bonding a lens block to ophthalmic lens blanks is provided. The tape comprises a polymeric backing and a pressure-sensitive adhesive. In a first preferred embodiment the surface of the backing is a blend of an olefin polymer with a polymer having acidic functionality. The blend may be formed as the backing layer, i.e., directly on the adhesive layer of the tape, or as the outer surface layer of a multilayered backing. In a second embodiment, the surface of the backing is a copolymer of an olefin monomer with a monomer having pendant acidic functionality. A lens block may be adhered to an ophthalmic lens blank by applying a section of the tape described above to an ophthalmic lens so that the pressure sensitive adhesive of the tape contacts the lens; conforming the tape to the compound surface of the lens; and attaching a lens block to at least a portion of the polymer backing layer. The tape may be made by extruding a polymeric backing material as described above; extruding a pressure-sensitive adhesive; and contacting the polymeric backing material and the pressure-sensitive adhesive. If desired, the polymeric backing material and the pressure sensitive adhesive may be coextruded to form the tape. In most preferred embodiments, the tape may be wound into a roll without a separate liner material.

A method of processing a lens is disclosed. A lens blank and a lens block are each provided with a structured surface having a plurality of tapered elements. The lens blank is releasably attached to the lens block by pressing the structured surface of the lens blank against the structured surface of the lens block, followed by subjecting the mounted lens blank to lens processing operations.

The invention provides, in a first embodiment, a blocking wax composition. The blocking wax comprises from about 50 to about 90 weight percent of a water-soluble continuous phase and from about 10 to about 50 weight percent of a discontinuous solid phase filler that is substantially inert to the continuous phase. The invention further provides a method for mounting a contact lens blank for machining.