A wearable device comprising a master unit and at least one slave unit, wherein the master unit comprises a first display and a first processing circuitry as well as a first memory, and the slave unit comprises a second display and a second processing circuitry as well as a second memory which is separate from the first memory, wherein the first memory and the second memory are both configured to comprise common three dimensional information to be rendered in the master unit and in the slave unit respectively, wherein the first processing circuitry is configured to: acquire at least one sensor signal from a sensor (250, 260, 270) comprised in the master unit; generate a synchronisation signal, based on the acquired sensor signal, for synchronising in time the output on the first display with the output on the second display; transmit the generated synchronisation signal to the slave unit; render the three dimensional information to be outputted in the first display; and transmit the rendered information to the first display for outputting the rendered information on the first display; and wherein the second processing circuitry is configured to: receive the synchronisation signal from the master unit; render the three dimensional information to be outputted in the second display, based on the received synchronisation signal; and transmit the rendered information to the second display for outputting the rendered information on the second display, wherein the first processing circuitry is further configured to transmit the generated synchronisation signal to the slave unit via a low bandwidth connection having a bandwidth of at most 2.1 Mbit/s, and no physically routed high-bandwidth video link is present between the master unit and the slave unit with cables. wherein the first memory and the second memory are both configured to comprise common three dimensional information to be rendered in the master unit and in the slave unit respectively, wherein the first processing circuitry is configured to: acquire at least one sensor signal from a sensor (250, 260, 270) comprised in the master unit; generate a synchronisation signal, based on the acquired sensor signal, for synchronising in time the output on the first display with the output on the second display; transmit the generated synchronisation signal to the slave unit; render the three dimensional information to be outputted in the first display; and transmit the rendered information to the first display for outputting the rendered information on the first display; and acquire at least one sensor signal from a sensor (250, 260, 270) comprised in the master unit; generate a synchronisation signal, based on the acquired sensor signal, for synchronising in time the output on the first display with the output on the second display; transmit the generated synchronisation signal to the slave unit; render the three dimensional information to be outputted in the first display; and transmit the rendered information to the first display for outputting the rendered information on the first display; and wherein the second processing circuitry is configured to: receive the synchronisation signal from the master unit; render the three dimensional information to be outputted in the second display, based on the received synchronisation signal; and transmit the rendered information to the second display for outputting the rendered information on the second display, receive the synchronisation signal from the master unit; render the three dimensional information to be outputted in the second display, based on the received synchronisation signal; and transmit the rendered information to the second display for outputting the rendered information on the second display, wherein the first processing circuitry is further configured to transmit the generated synchronisation signal to the slave unit via a low bandwidth connection having a bandwidth of at most 2.1 Mbit/s, and no physically routed high-bandwidth video link is present between the master unit and the slave unit with cables.