Single vision lenses

An optical lens element adapted for mounting in a frame of the wrap-around or shield type, such that the lens element is rotated temporally about a vertical axis through the optical centre thereof, the lens element including

• a front and back surface capable of forming a prescription (Rx) zone;
• and optionally
• a peripheral temporal zone;
• the front and/or back surface bearing a surface correction to at least partially adjust for errors including astigmatic and mean power errors.

An optical lens element adapted for mounting in a frame of the wrap-around or shield type, the lens element including

• a front and back surface capable of forming a prescription (Rx) zone;
• and optionally
• a peripheral temporal zone
• wherein the optical axis is decentred relative to the geometric axis of the lens element to provide for prismatic correction,
• the front and/or back surface bearing a surface correction to at least partially adjust for errors including astigmatic and mean power errors.

A laminate optical article adapted for mounting in a frame of the wrap-around or shield type, including

• a front lens element;
• a complementary back lens element, the front and back surfaces of the laminate optical article being capable of forming a prescription (Rx) zone;
• the front and/or back surface bearing a correction to at least partially adjust for error including astigmatic and mean power errors;
• the front and/or back lens element optionally including
• a peripheral temporal zone.

A laminate optical article adapted for mounting in a frame of the wrap-around or shield type, such that the laminate article is rotated temporally about a vertical axis through the optical centre thereof, including

• a front lens element;
• a complementary back lens element, the front and back surfaces of the laminate optical article being capable of forming a prescription (Rx) zone;
• the front and/or back surface bearing a correction to at least partially adjust for errors including astigmatic and mean power errors;
• the front and/or back lens element optionally including
• a peripheral temporal zone.

A method of designing an optical lens element adapted for mounting in a form of the wrap-around or shield type, which method includes

• providing
• mathematical or numerical representation of a surface of an optical lens element including a section designed to provide the desired prescription (Rx) in the prescription zone;
• and optionally adding thereto a mathematical or numerical representation of a peripheral temporal zone to define a complete lens surface;
• rotating and/or decentring the representation of the lens surface to permit mounting in a suitable frame;
• and
• modifying the representation of the lens surface to at least partially correct for astigmatic errors.

39 A method according to claim 38, including

• providing
• a mathematical or numerical representation of a surface of an optical lens element including a section designed to provide the desired prescription (Rx) in the prescription zone;
• and adding thereto
• a first mathematical or numerical representation of a peripheral temporal zone thereto;
• and
• a second mathematical or numerical representation of a transition section designed to smoothly blend the prescription section and peripheral temporal zone to define a complete lens surface;
• rotating and/or decentring the representation of the lens surface to permit mounting in a suitable frame;
• and
• modifying the representation of the lens surface to at least partially adjust for errors including astigmatic and mean power errors.

A method according to claim 39 wherein a surface of the optical lens element is represented by the following formulas

• sag=SAG R≦Ro,
• wherein R is the radius measured from the optical axis and A2, A4, A6 and A8 are coefficients that define power and asphericity;
• sag=SAG+DSAG R≧Ro.
• wherein Ro defines the periphery of the temporal region;
• and
• DSAG=B2(R−Ro)2+B4(R−Ro)4+B6(R−Ro)6+B8(R−Ro)8
• wherein B2, B4, B6 and B8 are coefficients that define power and asphericity.

Spectacles including

• a spectacle frame of the wrap-around type adapted to receive a pair of ophthalmic lenses such that each lens is rotated temporally about a vertical axis through the optical centre thereof;
• and
• a pair of optical lenses, each lens including
• a front and/or back surface capable of forming a prescription (Rx) surface;
• and
• a temporal zone
• the front and/or back surface bearing a surface correction to at least partially adjust for errors including astigmatic errors.