'Front of screen images increase visual discomfort'

Study: Demand on eye to focus on screens of mobile, 3D devices while simultaneously adjusting to distance of content causes discomfort.

iphone (photo credit: Marc Israel Sellem)
(photo credit: Marc Israel Sellem)
The root cause of visual discomfort experienced during prolonged viewing of mobile devices and other stereo 3D devices may be due to the demand on the eye to focus on the screen and simultaneously adjust to the distance of the content, researchers have found.
As part of a new Journal of Vision study, a research team observed the interaction between the viewing distance and the direction of the conflict, examining whether placing the content in front of or behind the screen affects viewer discomfort.
"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," explains author Martin S. Banks, professor of optometry and vision science, University of California, Berkeley.
The researchers found that devices such as cell phones and desktop displays that are viewed at a short distance, stereo content placed in front of the screen — appearing closer to the viewer and into the space of viewer's room — was less comfortable than content placed 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.