Multifocal diffractive ophthalmic lens and method of manufacture

A multifocal intraocular lens precursor assembly for fabrication of a finished lens, including:

• a first unfinished lens member having a thickness, an inner surface with an edge and a multifocal diffractive zone plate on the inner surface, the diffractive zone plate formed from material characterized by an index of refraction and imparting multifocal diffractive optical power to the finished lens;
• a second unfinished lens member having a thickness and an inner surface with an edge, the edge of the second lens member fixedly joined to the edge of the first lens member;
• a cavity defined by the inner surfaces of the first and second lens members adjacent the zone plate;
• a solid or fluid material within the cavity characterized by an index of refraction which is different than the index of refraction of the zone plate;
• and
• sufficient thickness on at least one of the first and second lens members to enable the fabrication of a smooth, curved outer surface on the lens member to impart refractive optical power to the finished lens.

A multifocal intraocular lens, including:

• a first lens member having a smooth outer surface and an inner surface with an edge about its perimeter and a multifocal diffractive zone plate, the diffractive zone plate characterized by an index of refraction and imparting multifocal diffractive optical power to the lens;
• a second lens member having a smooth outer surface and an inner surface with an edge about its perimeter, the edge of the second lens member fixedly joined to the edge of the first lens member;
• a curved outer surface on at least one of the first and second lens members, for imparting refractive optical power to the lens;
• a cavity adjacent the zone plate and defined by the inner surfaces of the first and second lens members;
• and
• a material within the cavity which is characterized by an index of refraction which is different than the index of refraction of the diffractive zone plate.

A multifocal intraocular ophthalmic lens, including:

• a lens having first and second smooth and opposed outer surfaces;
• a multifocal diffractive zone plate characterized by an index of refraction within the lens between the outer surfaces, for imparting multifocal diffractive optical power to the lens;
• a region of solid or fluid material characterized by an index of refraction which is different than the index of refraction of the zone plate, the region of material within the lens between the outer surfaces and in contact with the zone plate;
• and
• a curved outer surface on at least one of th first and second opposed outer surfaces, for imparting refractive optical power to the lens.

A method for manufacturing a multifocal intraocular lens, including:

• providing first and second lens members having outer surfaces and inner surfaces with edges about the perimeters, at least one of the lens members having a concave inner surface, at least one of the lens members having a multifocal diffractive zone plate characterized by an index of refraction on the inner surface for imparting diffractive multifocal optical power to the lens, and at least one of the lens members having a curved outer surface for imparting refractive optical power to the lens;
• joining the first and second lens members at their edges to form a cavity adjacent the zone plate defined by the inner surfaces of the first and second lens members;
• and
• filling the cavity with material characterized by an index of refraction which is different than the index of refraction of the multifocal diffractive zone plate.