A method and a device for activating a function of a device, preferably of a medical device. The method includes the steps of: detecting an actual state of the device using a camera, preferably an AR device, which is preferably AR glasses; comparing the actual state of the device with a desired state of the device using a CPU connected to the camera; transmitting, on the basis of the comparison, a command for starting the function of the device or a function test, preferably a function test, from the CPU to the device; and activating the function or the function test of the device on the basis of this command.