1. A head mounted display (HMD) device, comprising: a device body arranged to cover a first portion of a face of a user such that eyes of the user are hidden from view, wherein the HMD device, when worn by the user, is arranged to leave a second portion of the face of the user viewable; one or more sensors positioned on the device body that are arranged to track one or more of eye movement, eyelid movement and eyebrow movement of the user; and a display positioned on the device body that is arranged to display an image for the user when the HMD device is worn by the user.