Patent ID: 9310624
Filing Date: 2016-04-12
CPC Classification: A61F,A61L,C08F,C08K,C08L,G02B,G02C

Claim Text:
1. A multifocal ophthalmic device comprising a lens body being formed with a plurality of concentric annular zones separated by slanted steps, wherein said concentric zones effect both diffraction and refraction of incident light, while said steps are substantially devoid of any diffractive or refractive power, said lens body comprising a co-polymeric composition which comprises a polymeric backbone composed of a plurality of backbone units covalently linked to one another, said backbone units being derived from a pre-polymerization mixture of monomers which comprises: a first aromatic acrylate monomer, characterized as forming a first homopolymer having a refractive index that ranges from 1.50 to 1.53; a second aromatic acrylate monomer, characterized as forming a second homopolymer having a Tg lower by a range of 2° C. to 30° C. than a Tg of said first homopolymer; a third monomer, characterized as forming a third homopolymer having a Tg lower than 35° C.; a fourth monomer, characterized as forming a fourth homopolymer which is capable of absorbing water to at least 20% of the total weight of said fourth homopolymer; and a fifth monomer, being a crosslinking monomer, wherein: a concentration of said first aromatic acrylate monomer ranges from 50% to 60% of the total weight of the composition; a concentration of said second aromatic acrylate monomer ranges from 15% to 20% of the total weight of the composition; a concentration of said third monomer ranges from 10% to 15% of the total weight of the composition; a concentration of said fourth monomer ranges from 5% to 10% of the total weight of the composition; and a concentration of said fifth monomer ranges from 2% to 5% of the total weight of the composition.