Abstract: A method for controlling a display of a head mounted display (HMD) device, the method may include projecting on a display of the HMD device a given user interface element; sensing, by a sensor, a head movement of a user of the HMD device; unchanging a position of the projection of the given user interface element when a speed of the head movement is below a first speed threshold; and changing the position of the given user interface element when the speed of the head movement exceeds the first speed threshold.

Abstract: A method for feedback based maintenance wherein the method may include transmitting to an intermediate computerized system a first image that was acquired, at an acquisition point of time, by a head mounted display (HMD) mounted on a head of a first user; transmitting the first image from the intermediate computerized system and towards a computerized device of a second user; displaying on the computerized device of the second user the first image; receiving feedback, in response to the displaying and by the intermediate computerized system; generating, by the intermediate computerized system, an augmented image that comprises the first image and the feedback; transmitting to the HMD the augmented image; adjusting, by the HMD the augmented image to provide an amended augmented image that corresponds to visual information as viewed by the HMD at a display point in time; and displaying, by the HMD, the amended augmented image.