The invention relates to an optical system for single-chip or multi-chip LED lamps and luminaires, with heat sink and trim body, consisting of a glass lens which has various geometric shapes having a perimeter rim on the circular base thereof and a rubber seal of matching size via which the lens is inserted, optionally including a self-adhesive translucent polymer vinyl filter on the base of the lens, a trim having a special design in the shape of a top hat and a partially or completely translucent planar glass panel attached under the flange of said trim. The structure of the lens enables the perfect coupling thereof by fitting between the heat sink and the trim body, and can be used for manufacturing novel LED luminaires and modules, or for adapting existing LED luminaires and modules on the market, achieving, through the geometry of the lens, the filter and the planar glass panel, improved efficiency and light quality that is adequate for each specific use.