A turning device has two turning stations, each with a rotatable work piece spindle to hold a lens blank and each with a turning tool for the machining of a lens blank. A fabrication mechanism for the manufacturing of eyeglass lenses from lens blanks includes a milling device and the turning device, wherein the milling device has at least one milling station with a work piece holder to hold a lens blank and a milling tool for the machining of the lens blank. A loading device is configured to remove lens blanks from the milling device and load them into the turning device. A method for operating such a fabrication mechanism includes simultaneous machining of a third lens blank with the milling tool and a first and a second lens blank with the turning tools.