Beam combining device for combining light from a first light source and light from a second light source of a light-source device for a medical apparatus, comprising: a body (51, 52) made of a transparent material; a face which reflects in at least either a dichroic or polarization-dependent manner and is situated in or on the body (51, 52), which face is transparent to light having a first spectrum or a first polarization and reflects light having a second spectrum or a second polarization, for combining transmitted light with the first spectrum or the first polarization from the first light source and reflected light with the second spectrum or the second polarization from the second light source; a first light-entrance face on the body (51, 52), which light-entrance face is provided and arranged so that light enters the beam combining device through the light-entrance face, wherein the light of the second light source is coupled into the beam combining device via the first light-entrance face and reflected at the face which reflects in a dichroic or polarization-dependent manner, wherein the light of the first light source is coupled into the beam combining device via a second light-entrance face, wherein the light of the first light source passes through the face which reflects in a dichroic or polarization-dependent manner, characterized in that the first light-entrance face is curved and has the form of a section of a lateral face of a cylinder or of a cone and the lateral face of the body (51, 52) has a reflective coating away from the first light-entrance face, said reflective coating reflecting light that propagates within the body (51, 52), and the reflective coating has a window-shaped opening in the region of the first light-entrance face. a body (51, 52) made of a transparent material; a face which reflects in at least either a dichroic or polarization-dependent manner and is situated in or on the body (51, 52), which face is transparent to light having a first spectrum or a first polarization and reflects light having a second spectrum or a second polarization, for combining transmitted light with the first spectrum or the first polarization from the first light source and reflected light with the second spectrum or the second polarization from the second light source; a first light-entrance face on the body (51, 52), which light-entrance face is provided and arranged so that light enters the beam combining device through the light-entrance face, wherein the light of the second light source is coupled into the beam combining device via the first light-entrance face and reflected at the face which reflects in a dichroic or polarization-dependent manner, wherein the light of the first light source is coupled into the beam combining device via a second light-entrance face, wherein the light of the first light source passes through the face which reflects in a dichroic or polarization-dependent manner, characterized in that the first light-entrance face is curved and has the form of a section of a lateral face of a cylinder or of a cone and the lateral face of the body (51, 52) has a reflective coating away from the first light-entrance face, said reflective coating reflecting light that propagates within the body (51, 52), and the reflective coating has a window-shaped opening in the region of the first light-entrance face.