This application describes a head-mounted display (HMD) for use in virtual-reality (VR) environments. The systems and methods described herein may determine information about a real-world environment surrounding the user, a location of the user within the real-world environment, and/or a pose of the user within the real-world environment. Such information may allow the HMD to display images of the real-world environment in a pass-through manner and without detracting the user from the VR environment. In some instances, the HMD may pass-through images of the real-world environment based on one or more triggering events.