Abstract: A clear, impact modified, heat resistant polyvinyl chloride composition is provided comprising (a) at least one polyvinyl halide; (b) at least one clear impact modifier possessing a refractive index which is not more than about 2% above or below the refractive index of the polyvinyl halide; and (c) at least one clear heat modifier comprising a terpolymer obtained by the copolymerization of a vinyl aromatic monomer, an acrylonitrile and an alkyl acrylate or alkyl methacrylate, wherein the terpolymer possesses a refractive index which is not more than about 2% above or below the refractive index of the polyvinyl halide and possesses a weight average molecular weight ranging from about 75,000 to about 400,000.