Embodiments of an apparatus comprising a light guide including a proximal end, a distal end, a display positioned near the proximal end, an ocular measurement camera positioned at or near the proximal end to image ocular measurement radiation, a proximal optical element positioned in the light guide near the proximal end and a distal optical element positioned in the light guide near the distal end. The proximal optical element is optically coupled to the display, the ocular measurement camera and the distal optical element and the distal optical element is optically coupled to the proximal optical element, the ambient input region and an input/output optical element. Other embodiments are disclosed and claimed.