Method for operating a display device of a motor vehicle, wherein the display device comprises a display screen unit with a display surface, wherein the display surface comprises several predetermined subareas (24, 26, 28), and wherein a sight protection element of the display screen unit is designed to set for each of the subareas (24, 26, 28) a respective degree of a transparency, the method comprising, performed by a control module: - providing the display screen unit in a basic mode, in which the sight protection element sets the same degree of transparency for each of the subareas (24, 26, 28) in a basic value, wherein the basic value is a value for a first degree of transparency, - checking whether an unlocking signal is given which grants authorization of a user of the motor vehicle for using the display screen unit in a predetermined subarea unlock mode that predetermines an unlock value describing a different degree of transparency than the one with the basic value for at least one of the subareas (24, 26, 28, S2), and - in case the authorization is given: changing the degree of transparency only of the subareas (24, 26, 28) predetermined by the unlock signal, by means of the sight protection element, to the unlock value, and thereby providing the display screen unit in the predetermined subarea unlock mode; wherein the method is characterized in that, in the predetermined subarea unlock mode: - a subarea that is central with regard to an extension of the display screen unit remains opaque as in the basic mode, said central subarea displaying a graphical element; and - the sight protection element for at least two subareas (24, 28) flanking said central subarea sets the degree of transparency to the unlock value to turn the flanking subareas transparent. the method comprising, performed by a control module: - providing the display screen unit in a basic mode, in which the sight protection element sets the same degree of transparency for each of the subareas (24, 26, 28) in a basic value, wherein the basic value is a value for a first degree of transparency, - checking whether an unlocking signal is given which grants authorization of a user of the motor vehicle for using the display screen unit in a predetermined subarea unlock mode that predetermines an unlock value describing a different degree of transparency than the one with the basic value for at least one of the subareas (24, 26, 28, S2), and - in case the authorization is given: changing the degree of transparency only of the subareas (24, 26, 28) predetermined by the unlock signal, by means of the sight protection element, to the unlock value, and thereby providing the display screen unit in the predetermined subarea unlock mode; - providing the display screen unit in a basic mode, in which the sight protection element sets the same degree of transparency for each of the subareas (24, 26, 28) in a basic value, wherein the basic value is a value for a first degree of transparency, - checking whether an unlocking signal is given which grants authorization of a user of the motor vehicle for using the display screen unit in a predetermined subarea unlock mode that predetermines an unlock value describing a different degree of transparency than the one with the basic value for at least one of the subareas (24, 26, 28, S2), and - in case the authorization is given: changing the degree of transparency only of the subareas (24, 26, 28) predetermined by the unlock signal, by means of the sight protection element, to the unlock value, and thereby providing the display screen unit in the predetermined subarea unlock mode; wherein the method is characterized in that, in the predetermined subarea unlock mode: - a subarea that is central with regard to an extension of the display screen unit remains opaque as in the basic mode, said central subarea displaying a graphical element; and - the sight protection element for at least two subareas (24, 28) flanking said central subarea sets the degree of transparency to the unlock value to turn the flanking subareas transparent. - a subarea that is central with regard to an extension of the display screen unit remains opaque as in the basic mode, said central subarea displaying a graphical element; and - the sight protection element for at least two subareas (24, 28) flanking said central subarea sets the degree of transparency to the unlock value to turn the flanking subareas transparent.