Abstract: Articles having an interference coating which reflects infrared energy are disclosed. The coating has a period of three layers in which the first and third layers are a refractory dielectric material and the intermediate, or second layer, is silver. If the period is repeated once, the cut-off between transmission and reflection is sharper than the coating having a single period.

Abstract: There is disclosed a glass ophthalmic lens including an ion-exchanged antireflection coating. Metal oxide films including TiO.sub.2, CeO.sub.2, ZrO.sub.2, La.sub.2 O.sub.3, Nd.sub.2 O.sub.3, Al.sub.2 O.sub.3, and SiO.sub.2 when evaporated on glass lenses in a vacuum chamber by electron-beam techniques form hard optical coatings which are chemically stabile at high temperatures and allow potassium and sodium ions to traverse the thickness thereof without changing chemical composition or physical integrity thereby enhancing ability of glass lenses to be ion-exchanged in a conventional ion-exchange treatment. This allows antireflection coated glass lenses to pass impact-resistant standards ANZI Z80.1 for prescription ophthalmic lenses and USAS Z87.1 for safety lenses.

Abstract: There is disclosed a process for improving the adhesion of an evaporable glass coating on a synthetic polymer sheet material by the application of a base vitreous coating of a mixture of silicon dioxide and silicon monoxide by evaporating silicon monoxide under vacuum in an oxygen atmosphere so that in addition to silicon monoxide, a silicon dioxide condensate is condensed on the outer surface of the sheet. An outer vitreous coating is subsequently applied over said base coating. The evaporative glass outer coating can be formed essentially from boron oxide and silicon dioxide containing less than 5% by weight of sodium oxide. The evaporative glass coating can also be of fused silica, or a boro-silicate glass sold under the trademark "Pyrex".

Abstract: There is disclosed a process for improving the adhesion of an evaporable glass coating on a synthetic polymer lens by the application of a base vitreous coating of a mixture of silicon dioxide and silicon monoxide by evaporating silicon monoxide under vacuum in an oxygen atmosphere so that in addition to silicon monoxide, a silicon dioxide condensate is condensed on the outer surface of the lens. An outer vitreous coating is subsequently applied over said base coating. The evaporative glass outer coating can be formed essentially from boron oxide and silicon dioxide containing less than 5% by weight of sodium oxide. The evaporative glass coating can also be of fused silica, or a boro-silicate glass sold under the trademark "Pyrex".