| 摘要 |
A gas permeable (GP) ocular lens composition and method of formation arc dis closed 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, selecte d for basic GP lens characteristics such as rigidity, structural stabilty and desi red refractive index, are combined in an interpenetratin g polymer network (IPN) structure forming a thermoplastic composition having optical c larity/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; pr eferably about 5,000-40,000 psi: and more preferably abo ut 20,000-40,000 psi. In one embodiment, the lens comprises a central portion a nd an annular portion of different characteristics. In another cosmetic embodiment, a film with an image of an iris is encapsulated in the composition.
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