Patent ID: 8344046

Claim:
An ink for printing a color image on an ophthalmic lens using an inkjet printing system, comprising: a solvent, a colorant, a binder polymer, a humectant, a surfactant, and optionally a crosslinker, wherein the ink is characterized by having a surface tension of from about 20 mN/m to about 60 mN/m, a viscosity of less than 50 centipoise, and good adhesion to an ophthalmic lens, with said ink passes a finger rubbing test and a sterilization surviving test, wherein the solvent is selected from water, water/ethanol, water/isopropanol, water/glycerol, water/diethylene glycol, cyclopentanone and cyclohexanone, wherein the amount of the solvent is from 70% and 95% by weight, wherein the amount of the binder polymer is from 1% to 30% by weight, and wherein the amount of the colorant is from 0.5% to about 8% by weight, wherein the colorant comprises at least a pigment, wherein the amount of the humectant is from 1 to 15% by weight, wherein the amount of the surfactant is from 0.1 to 0.5% by weight, and wherein the amount of the crosslinker is from 0 to 10% by weight.