The disclosed head-mounted display assemblies may include a first eyecup and a second eyecup that are configured for positioning in front of intended locations of a user's eyes. The first eyecup and the second eyecup may be movable relative to each other to adjust for an interpupillary distance of the user's eyes. The head-mounted display assemblies may also include a single near-eye display screen configured for displaying an image to the user through the first eyecup and the second eyecup. A flexible shroud may be positioned to provide a seal between a first interior volume of the first eyecup, a second interior volume of the second eyecup, and the single near-eye display screen. Various other methods, devices, systems, and assemblies are also disclosed.