In the 1970s, there were further developments in the company's ophthalmic and glass fiber operations. In 1979, the company's ophthalmic interests were much expanded with the acquisition of the Australia-based Sola Holdings Ltd, a world-leading manufacturer of plastic spectacle lenses.
A new factory for manufacturing glass fiber reinforcements was opened in Wrexham in 1971 and in 1976 a new factory at Pontyfelin, South Wales increased capacity for insulation products.