An illuminating device, comprising: a light source; and a light-transmitting article formed from a thermoplastic composition, positioned to provide a light transmission path from the light source through the light-transmitting article, with a distance, d, between the light source and the light-transmitting article of less than 40 mm, the light transmission path extending through the light-transmitting article and optionally through other light-transmitting article(s) comprising the thermoplastic composition such that the total distance, p, of the light transmission path through the light-transmitting article is at least 3 mm; wherein the thermoplastic composition comprises a polycarbonate having repeating structural carbonate units according to the formula in which at least 60 percent of the total number of R 1 groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic; the polycarbonate having been prepared through an interfacial polymerization process from BPA monomer having an organic purity higher than 99.70 % by weight and having a hydroxyl content lower than 150 ppm by weight; 0.01 wt.% to 0.30 wt.%, based on the total weight of the thermoplastic composition, of an epoxy additive having at least two epoxy groups per molecule; and 0.01 wt.% to 0.30 wt.%, based on the total weight of the thermoplastic composition, of a phenolic diphosphite derived from pentaerythritol; wherein the thermoplastic composition has a sulfur content lower than 2 ppm, and wherein the thermoplastic composition exhibits a dE (2000hrs.) value of less than 2.0 after 2000 hours of heat aging at 130°C of a 2.5 mm thick molded plaque of the thermoplastic composition, measured according ISO 11664-4:2008 /CIE S 014-4/E:2007 using CIE illuminant D65, wherein dE is calculated based on a comparison between an un-aged 2.5 mm thick molded plaque of the thermoplastic composition and the heat aged 2.5 mm thick molded plaque of the thermoplastic composition. a light source; and a light-transmitting article formed from a thermoplastic composition, positioned to provide a light transmission path from the light source through the light-transmitting article, with a distance, d, between the light source and the light-transmitting article of less than 40 mm, the light transmission path extending through the light-transmitting article and optionally through other light-transmitting article(s) comprising the thermoplastic composition such that the total distance, p, of the light transmission path through the light-transmitting article is at least 3 mm; wherein the thermoplastic composition comprises a polycarbonate having repeating structural carbonate units according to the formula in which at least 60 percent of the total number of R 1 groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic; the polycarbonate having been prepared through an interfacial polymerization process from BPA monomer having an organic purity higher than 99.70 % by weight and having a hydroxyl content lower than 150 ppm by weight; 0.01 wt.% to 0.30 wt.%, based on the total weight of the thermoplastic composition, of an epoxy additive having at least two epoxy groups per molecule; and 0.01 wt.% to 0.30 wt.%, based on the total weight of the thermoplastic composition, of a phenolic diphosphite derived from pentaerythritol; wherein the thermoplastic composition has a sulfur content lower than 2 ppm, and wherein the thermoplastic composition exhibits a dE (2000hrs.) value of less than 2.0 after 2000 hours of heat aging at 130°C of a 2.5 mm thick molded plaque of the thermoplastic composition, measured according ISO 11664-4:2008 /CIE S 014-4/E:2007 using CIE illuminant D65, wherein dE is calculated based on a comparison between an un-aged 2.5 mm thick molded plaque of the thermoplastic composition and the heat aged 2.5 mm thick molded plaque of the thermoplastic composition.