  We are experiencing an upcoming trend of using head mounted display systems
in games and serious games, which is likely to become an established practice
in the near future. While these systems provide highly immersive experiences,
many users have been reporting discomfort symptoms, such as nausea, sickness,
and headaches, among others. When using VR for health applications, this is
more critical, since the discomfort may interfere a lot in treatments. In this
work we discuss possible causes of these issues, and present possible solutions
as design guidelines that may mitigate them. In this context, we go deeper
within a dynamic focus solution to reduce discomfort in immersive virtual
environments, when using first-person navigation. This solution applies an
heuristic model of visual attention that works in real time. This work also
discusses a case study (as a first-person spatial shooter demo) that applies
this solution and the proposed design guidelines.
