Imperviousness to light refers to the resistance of objects or materials to light penetration. Synonyms for this phrase may include light impermeability, light resistance, light-proofness, opacity, and imperviousness to radiation. All these terms imply that an object, surface, or material is incapable of letting light pass through it. These synonyms are commonly used in various industries, including optics, electronics, and construction. In optics, materials with high opacity are useful for blocking light and creating polarizers, filters, and coatings. In electronics, imperviousness to radiation is essential in designing radiation-hardened devices. In construction, materials with light impermeability properties contribute to energy efficiency, insulation, and privacy.