A head-mounted display (HMD) immerses users in a virtual world, but separates them from outsiders in the real world. We present FrontFace, which is a novel HMD that combines an eye-tracker with a front-facing screen, to lower the communication barrier between HMD users and outsiders. The front-facing screen reveals user attention (e.g., the users eye motions) and user presence in the virtual or real world by displaying the scene in the virtual world or a skin background respectively, enabling eye-contact interactions between the HMD user and the outsiders. FrontFace has the following benefits. Firstly, it communicates the presence of the HMD user to outsiders; secondly, it reveals the player's visual attention by introducing the HMD users originally occluded eye motions, enabling outsiders to make sense of the HMD user's reaction in the virtual world or the real world. Three interactive techniques for the outsiders to initiate communication to HMD users are proposed: they are tap-trigger, hand-gesture trigger, and voice-trigger interactions. A small focus group provided feedback.