<P> A 2016 publication assessed the effects of exposure to 2D vs 3D dissection videos on nine pathology resident physicians, using self - reported physiologic symptoms . Watching the content in 3D vs 2D did not increase simulator sickness . Although the average simulator sickness questionnaire score did increase with time, statistical analysis does not suggest significance . </P> <P> The persistent tracking required by all VR systems makes the technology particularly useful for, and vulnerable to, mass surveillance . The expansion of VR will increase the potential and reduce the costs for information gathering of personal actions, movements and responses . In networked VR spaces with capacity for public interaction, there is the potential for unexpected modifications of the environment . </P> <P> In addition, there are conceptual and philosophical considerations and implications associated with the use of virtual reality . What the phrase "virtual reality" means or refers to can be ambiguous . Mychilo S. Cline argued in 2005 that through virtual reality techniques will be developed to influence human behavior, interpersonal communication, and cognition . In the book The Metaphysics of Virtual Reality by Michael R. Heim, seven different concepts of virtual reality are identified: simulation, interaction, artificiality, immersion, telepresence, full - body immersion, and network communication . As we spend more and more time in virtual space, there could be a gradual "migration to virtual space", resulting in important changes in economics, worldview, and culture . Philosophical implications of VR are discussed in books, including Philip Zhai's Get Real: A Philosophical Adventure in Virtual Reality (1998) and Digital Sensations: Space, Identity and Embodiment in Virtual Reality (1999), written by Ken Hillis . </P>

Introduction to virtual reality and multimedia in hindi