The prolonged viewing of mobile devices and other stereo 3D devices leads to visual discomfort, fatigue and even headaches. A Journal of Vision study says the reason behind this may be the strain on the eyes while focusing on the screen and simultaneously adjusting to the distance of the content.
Referred to as vergence-accommodation, this conflict and its effect on viewers of stereo 3D displays are detailed in a recent article, 'The Zone of Comfort: Predicting Visual Discomfort with Stereo Displays'. “When watching stereo 3D displays, the eyes must focus, or accommodate, to the distance of the screen because that's where the light comes from. The eyes must also converge to the distance of the stereo content, which may be in front of or behind the screen,” explains author Martin S Banks, professor of optometry and vision science, University of California, Berkeley.