The root cause may be the demand on our eyes to focus on the screen and simultaneously adjust to the distance of the content. Scientifically referred to as vergence-accommodation, this conflict and its effect on viewers of stereo 3D displays are detailed in a recent Journal of Vision article.

'When watching stereo 3D displays, the eyes must focus — that is, accommodate — to the distance of the screen because that’s where the light comes from. At the same time, the eyes must converge to the distance of the stereo content, which may be in front of or behind the screen.

'Discomfort associated with viewing Stereo 3D is a major problem that may limit the use of technology', says Banks. 'We hope that our findings will inspire more research in this area'.

'This is an area of research where basic science meets application and we hope that the science can proceed quickly enough to keep up with the increasingly widespread use of the technology', adds Banks.