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 clarity afterward than when they watched 2D video. The disparity between the depth of the screen and the depth of the 3D image caused the most problems, though 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 and 2D 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 the eyes are trying to focus on. 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. The self-reported differences between 3D and 2D 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 much more uncomfortable to look at when viewed in a living room.
Unfortunately for Samsung, financial supporters of the study and manufacturers of 3D TVs, the research appears to indicate that they're hurting the eyes of their customers.