Method for forming plastic optical quality spectacle lenses

A method for making a finished lens having a multifocal or progressive region, said method comprising:

• providing a mold having a molding surface;
• providing an optical quality resin composition containing an ultraviolet light initiator;
• providing preformed plastic lens of optical quality having a predetermined lens correction at its optical center, said lens having a bonding surface;
• said mold having a first complementary surface of a curvature substantially the same as that of the bonding surface on the preformed plastic lens and a second surface corresponding to a multifocal region of a lens, said multifocal region constituting a minor portion of the mold;
• placing said resin composition of a material of a different composition than said lens on said mold;
• arranging said preformed lens with said mold such that the bonding surface of said preformed lens and said mold form a cavity enclosing said resin composition, said cavity having a first portion cooperating with said mold to form a relatively thin space therebetween of substantially constant thickness and a second portion cooperating with said mold to form said multifocal region;
• curing the outer surface of said resin with UV light having a first intensity and subsequently curing resin beneath said surface with UV light having a second intensity;
• and
• maintaining pressure on said resin composition during said curing step;
• wherein the lens correction of said resulting lens is substantially the same as said predetermined lens correction of said preformed lens and the only substantially change in power being substantially in the vicinity of said multifocal region.

A method for making a finished lens having a multifocal or progressive region, said method comprising:

• providing a mold having a molding surface;
• providing an optical quality resin composition containing an ultraviolet light initiator;
• providing a preformed plastic lens of optical quality having a predetermined lens correction at its optical center, said lens having a bonding surface;
• said mold having a first complementary surface of a curvature substantially the same as that of the bonding surface on the preformed plastic lens and a second surface corresponding to a multifocal region of a lens, said multifocal region constituting a minor portion of the mold;
• said resin comprising a first initiator that facilitates surface curing prior to curing a resin beneath said surface and a second initiator for facilitating curing of resin between the surface and said preform lens substantially after said surface curing;
• placing said resin composition of a material of a different composition than said lens on said mold;
• arranging said preformed lens with said mold such that the bonding surface of said preformed lens and said mold form a cavity enclosing said resin composition, said cavity having a first portion cooperating with said mold to form a relatively thin space therebetween of substantially constant thickness and a second portion cooperating with said mold to form said multifocal region;
• curing said resin composition with an ultraviolet light source;
• and
• maintaining pressure on said resin composition during said curing step;
• wherein the lens correction of said resulting lens is substantially the same as said predetermined lens correction of said preformed lens and the only substantial change in power being substantially in the vicinity of said multifocal region.

A method for making a finished lens having a multifocal or progressive region, said method comprising:

• providing a mold having a molding surface;
• providing an optical quality resin cmoposition containing an ultraviolet light initiator;
• providing a preformed plastic lens aof optical quality having a predetermined lens correction at its otical center, said lens having a bonding surface;
• said mold having a first complementary surface of a curvature substantially the same as that of the bonding surface on the preformed plastic lens and a second surface corresponding to a multifocal region of a lens, said multifocal region constituting a minor portion of the mold;
• placing said resin composition of a material of a different composition than said lens on said mold;
• arranging said preformed lens with said mold such that the bonding surface of said preformed lens and said mold form a cavity enclosing said resin composition, said cavity having a first portion cooperating with said mold to form a relatively thin space therebetween of substantially constant thickness and a second portion cooperating with said mold to form said multifocal region;
• curing said resin composition with an ultraviolet light source;
• oscillating said lens and said mold during said curing step;
• and
• maintaining pressure on said resin composition during said curing step;
• wherein the lens correction of said resulting lens is substantially the same as said predetermined lens correction of said preformed lens and the only substantial change in power being substantially in the vicinity of said multifocal region.

A method for making a finished lens having a multifocal or progressive region, said method comprising:

• providing a mold having a molding surface;
• providing an optical quality resin composition containing an ultraviolet light initiator;
• providing a preformed plastic lens of optical quality having a predetermined lens correction, said lens having a bonding surface;
• said lens having been coated with a hard coat material;
• said mold having a first complementary surface to that of the bonding surface on the preformed plastic lens and a second surface corresponding to a multifocal region of a lens, said multifocal region constituting a minor portion of the mold;
• placing said resin composition of a material of a different composition than said lens on said mold;
• arranging said preformed lens with said mold such that the bonding surface of said preformed lens and said mold form a cavity enclosing said resin composition, said cavity having a first portion cooperating with said mold to form a relatively thin space therebetween of substantially constant thickness and a second portion cooperating with said mold to form said multifocal region;
• curing said resin composition by curing the outer surface of said resin with UV light having a first wavelength and subsequently curing resin beneath said surface with UV light having a second wavelength;
• and
• wherein the lens correction of said resulting lens is substantially the same as said predetermined lens correction of said preformed lens and the only substantial change in power being substantially in the vicinity of said multifocal region.

A method for making a finished lens, said method comprising:

• providing a mold having a molding surface;
• providing an optical quality resin composition containing an initiator;
• providing a preform plastic lens of optical quality having a predetermined lens correction, said lens having a bonding surface;
• said mold having a complementary surface to that of the bonding surface on the preformed plastic lens;
• placing said resin composition on said mold;
• arranging said preformed lens with said mold such that the bonding surface of said preformed lens and said mold form a cavity enclosing said resin composition and cooperating therewith to form a relatively thin space therebetween;
• curing a surface portion of said resin composition adjacent the mold prior to curing the portion of the resin between said surface portion and said lens, said curing step being accomplished to harden said surface portion of said resin prior to hardening of the resin between the surface portion of the lens to substantially avoid unwanted astigmatism during the curing process.