Abstract: This invention provides novel compositions curable to resins and particularly provides oxygen permeable, inherently wettable optical devices useful as eye contact or intraocular lenses. The lenses are composed of a cured polysiloxane resin having an advancing water-in-air contact angle of no greater than 80.degree.. The polysiloxane resin is prepared from a catalyzed mixture of an acrylate-functional polysiloxane composition and an organosilicon cross-linking agent containing silicon hydride radicals. The acrylate-functional polysiloxane composition contains a sufficient amount of aliphatically unsaturated hydrocarbon radicals (e.g., vinyl radicals) other than acrylate-functional radicals to enable that composition to react on a mole to mole basis with the cross-linking agent to produce a cured polysiloxane resin.

Abstract: Platinum-catalyzed mixtures of H(CH.sub.3).sub.2 SiO--(C.sub.6 H.sub.5).sub.2 SiOSi(CH).sub.2 H and monophenylsiloxy/dimethylvinylsiloxy copolymer cure to give a strong flexible resin having thermal shock resistance.