Internal and external Field of View: computer games and cybersickness

In an experiment with a computer game environment, we studied the effect of Field-of-View (FOV) on cybersickness. In particular, we examined the effect of differences between the internal FOV (IFOV, the FOV which the graphics generator is using to render its images) and the external FOV (EFOV, the FOV of the presented images as seen from the physical viewpoint of the observer). We hypothesized that incongruent IFOVs and EFOVs would lead to a larger incidence of cybersickness. However, this was not found, and the opposite seems to be true instead. The unexpected result may be explained by the relative large differences between IFOV and EFOV we used.