Everybody has been talking about new emerging products in augmented reality (AR) and their potential to enhance our daily life and work. The AR technology has been around for quite a while and various use cases have been thought and tested. Clearly, the new AR Systems (e.g. Vuzix m100, Google Glasses) will bring its use to a new level. For planning, designing and reviewing of innovative AR systems and their application, virtual reality (VR) technology can be supportive. Virtual prototypes of AR Systems can be expired and evaluated within a VR environment (e.g. CAVE).This paper proposes the virtualization of AR displays within VR environments and discusses requirements. A user study investigates the necessary pixel density for the legibility of a virtual display in order to verify the significance of guidelines given by ISO 9241-300. Furthermore, equations examine the suitability of various VR systems for display virtualization within VR environments. This will enable reviews of various display systems in a virtual manner.