It is pointed out that the basic model of "artificial daylight" in the open is not appropriate for reading and writing. Man has become accustomed to reading with daylight coming from the side through a window. Daylight indoors differs from daylight outfoord through a yellowish tendency, to which the human eye is accustomed in the presence of the usual light intensity indoors. Fluorescent "daylight" or "neutral white" lights are therefore experienced by the human eye as too blue and should only be used for special purposes with very high luminous intensities. Daylight unfortunately cannot yet be completely imitated. Hence genuine daylight should still be used as long as possible and artificial light should even today be regarded only as a replacement. Practical advice is given on mixed light with incandescent and fluorescent lamps, and also on general illumination with additional illumination for the place of work.