Abstract: When blank-molded optical glass bodies are manufactured according to known methods based on blank-molding technology, the product exhibits rings in the glass and folds as well as an impression that precisely coincides with the contact surface of the parison inside the pressing die before the pressing operation. These defects are not permissible in blank-molded lenses, however, because they cause an undesirable optical effect such as changing the glare value in automobile headlights. Such defects are process-dependent and are caused by the fact that the transfer of the parison to the pressing die and the pressing itself are two separate operations that are performed with different tools.

Abstract: A high-refractive index phototropic glass having a refractive index of 1.69 to more than 1.7, an Abbe coefficient of at least 35 and a density of at most 3.5 g/cm.sup.3, has a composition (in % by weight based on oxide) of: SiO.sub.2 15-33; B.sub.2 O.sub.3 12-22; .SIGMA. SiO.sub.2 +B.sub.2 O.sub.3 30-50; Li.sub.2 O 0.5-5.0; Na.sub.2 O 0-3; K.sub.2 O 0-11; .SIGMA. alkali oxides 4-12; BaO 0-23; SrO 0-23; .SIGMA. SrO+BaO 0-23; ZrO.sub.2 5-14; Nb.sub.2 O.sub.5 15-24; Ta.sub.2 O.sub.5 2-11. As the carrier of the phototropism, the glass also has 0.10 to 0.35 of Ag.sub.2 O; 0.15-0.65 of Cl; 0.15-0.45 of Br and 0.005-0.030 of CuO. The glass can also be doped with 1-3 ppm of gold or one or more platinum metals, especially palladium.

Abstract: A rearview mirror suitable for vehicles, especially motor vehicles, is composed of a transparent substrate, preferably of soda silica glass and a rear reflection coating comprising a metal mirror layer, preferably chromium, and a dielectric triple interference layer system placed between the metal mirror layer and the transparent substrate. The triple interference layer system comprises, in contact with the metal layer, a dielectric layer having a high refractive index, e.g., titanium dioxide, a next layer having a low refractive index, e.g., silicon dioxide, and next a dielectric layer having a medium refractive index, e.g., a mixed TiO.sub.2 and SiO.sub.2 layer. With the selection of suitable layer thicknesses, a total reflection of at least 40% and a blue reflection tint, independent of the viewing angle, are attained.

Abstract: Dark blue dyed furnace sight glass of soda-lime-silica further containing carbon and oxides of iron and cobalt with substantially no infrared transmission and which sight glass affords a view of details in the melting operation. Other ingredients may include K.sub.2 O, MgO, Al.sub.2 O.sub.3 or ZrO.sub.2.

Abstract: A phototropic multilayered glass sheet incorporating at least two interfacially laminated layers, one layer consisting of a nonphototropic carrier glass, and at least one other layer consisting of a phototropic glass. In manufacture, at least one of the glass streams is characterized by having a viscosity of less than 10.sup.7.6 d PAS at the location where the streams are brought together.