Research into the side effects of VR use is a complex and difficult business and it is clear that concerns do remain about the effects of using such systems. Academic research does show that some symptoms occur whilst using VR tools and that these effects (such as nausea) can be quite debilitating in the short term. Whether or not there is a long term effect is difficult to determine, partly due to the fact that VR techniques are relatively new and are constantly evolving.
It is also clear that the factors involved in the genesis of symptoms are incredibly complex. Here, there is a complex interaction between the characteristics of the user, the type of system being used and the type of task that is being carried out. Given that there is a large variation between individuals, a huge number of equipment permutations and a vast number of tasks one can see that predicting accurately the effect of any one task in a specific system implementation on a single user is virtually impossible.
The type of system being used certainly has a big impact in the genesis of symptoms. Problems associated with desktop use are well understood, and regulations are in place to determine good working practice. At the other end of the scale are fully immersive systems where current technologies are being pushed to the limit. Although these systems provide the most compelling immersive effect, the genesis of many symptoms have been linked to their use. Somewhere in between these two implementations lie semi-immersive systems. Although it would be reasonable to expect that such systems may cause the genesis of symptoms such as simulator sickness, problems such as immersion injuries, the physical discomfort of an HMD and system lags are minimised. These considerations, and the fact that a reasonably powerful sense of immersion can still be achieved with semi-immersive large screen systems, explain the current trend towards their use. Indeed, many of the VR reality centres currently in use concentrate on semi-immersive multi-user implementations rather than fully-immersive single user systems.
Clearly, it is important for any potential VR users to understand the potential of each implementation for the genesis of symptoms. When one chooses a VR system care must be taken to look at the tasks for which the system will be used and the potential user population. If the use of a fully immersive system is imperative for the task then one must understand the health and safety implications. Similarly, if one chooses a desktop system to minimise health and safety problems, one loses the powerful sense of immersion provided by the other implementations. The most important aspect is that the user makes an informed decision and provides a VR set-up that takes into account the needs of the user(s) as well as the demands of the task(s).
Future developments in hardware and software may mean that this scenario will change. Developers are aware of the issues involved and are striving to overcome them. HMD design continues to improve with lighter headsets and better displays with greater fields of view and higher resolution. The effect that this will have on symptoms is also difficult to determine. One could argue that a more realistic experience with minimised lags and more realistic display technologies would reduce the onset of various symptoms as some of the proposed causative factors have been reduced. Not all are in agreement with this hypothesis however, and a quote form Computer Graphics (1992, p. 61) reads
"....because of technical improvements, sickness will be more frequent because of the improved ability to create virtual environments involving vehicle motions which are naturally nauseogenic."
If hardware improvements may mean a decrease in physical problems and an arguable reduction in physiological symptoms, what do they imply for psychological problems? Will a more realistic virtual experience provide more powerful psychological cues for the user, making it more difficult to determine real from synthetic? If so, will this lead to greater problems for users? The flip side of this coin is the idea that such improvements may make VR an even more powerful tool.
Recent developments such as the adoption of VRML, improvements in hardware design and the almost constant increases in PC computing power mean that VR technologies are now available to an even greater user population at more affordable prices. Ultimately, it is the users who will decide whether the benefits of VR outweigh the problems. Presently, human factors research has improved awareness of the problems that may occur and to date, none have been shown to be long-term or a serious threat to well being. These problems can however, bring about a reluctance on the part of the consumer to buy and use such equipment and if this reluctance is not addressed, the future potential of VR to have a beneficial effect on our lives may be diminished.
Graphics Multimedia Virtual Environments Visualisation Contents