OCULAR LENS COMPOSITION AND METHOD OF FORMATION

摘要

A gas permeable (GP) ocular lens composition and method of formation are disclosed wherein 98-70 % by wgt. of a first polymer component, selected for desired characteristics including gas permeability, and 2-30 % by wgt. of a second polymer component, selected for basic GP lens characteristics such as rigidity, structural stabilty and desired refractive index, are combined in an interpenetrating polymer network (IPN) structure forming a thermoplastic composition having optical clarity/compatibility and facilitating low cost formation by molding or thermoforming. The first polymer component is a block co-polymer of first and second monomers. The resulting lens composition has a flexure modulus in the range of about 2,000-50,000 psi; preferably about 5,000-40,000 psi; and more preferably about 20,000-40,000 psi. In one embodiment, the lens comprises a central portion and an annular portion of different characteristics. In another cosmetic embodiment, a film with an image of an iris is encapsulated in the composition.