Certain kinds of 3D displays cause extra eye fatigue, according to a study published by the Journal of Vision today that was funded in part by Samsung's R&D arm. A group of researchers from the University of Califonia-Berkeley found that when test subjects watched 3D displays, they reported more eye strain and fatigue and less vision with changes in depth of the screen and the depth of the 3D image. Researchers also found the relationship between image depth and nearness of the screen also played a role in eye strain.
Twenty-four participants in the study were shown 3D video at various viewing distances, and then responded to questionnaires on their eye fatigue, neck and back pain, and vision clarity. In the video clips, the authors were varying the focal point, which is the surface of the screen, and the vergence distance, which is where in the image on which the eyes are fixating. For 2D video, these points are always one and the same, but in 3D video the vergence distance varies, and can be either deeper than the surface of the screen or in front of it.
The participants responded that they experienced more eye strain and fatigue from the video with different vergence and focal distances, a feature of 3D that has long been supposed to cause eye strain (particularly when the two distances did not mimic a realistic portrayal of three dimensions). The self-reported differences were not drastic, but they were significant.
A second part of the study found that though 3D was fatiguing in general, the participants had more problems with distant displays showing an image with a vergence distance deeper than the screen and with near displays showing images popping out of the screen.
This research is highly relevant to 3D content designers, who could determine what to recess or pop out of the screen based on the expected viewer distance. However, the study also means that 3D video that is more comfortably viewed in a movie theater is necessarily more uncomfortable to look at when viewed in a living room.
(Update: Samsung and the authors of the study have noted that the purpose of this study was to determine not whether 3D visuals cause harm, but which types of 3D conditions can cause discomfort. Corrections have been made to the article throughout.)
Journal of Vision, 2011. DOI: 10.1167/11.8.11
Listing image by Photograph by Rebecca Cottrell