Benefits of Matching Accommodative Demands to Vergence Demands in a Binocular Head-Mounted Display: A Study on Stereo Fusion Times

Current head-mounted displays (HMDs) provide only a fixed lens focus. Viewers have to decouple their accommodation and vergence responses when viewing stereoscopic images presented on an HMD. This study investigates the time taken to fuse a pair of stereoscopic images displayed on an HMD when the accommodative demand is matched to the vergence demand. Four testing conditions exhausting the factorial combinations of accommodative demands (2.5 D and 0.5 D) and vergence demands (2.5 MA and 0.5 MA) were investigated. The results indicate that viewers take a significantly shorter amount of time to fuse a pair of stereoscopic images (i.e., fusion time) when the accommodative demand and the stereoscopic depth cues match. Further analysis suggests that an unnatural demand for the eyes to verge toward stereoscopic images whose stereo depth is farther than the accommodative demand is associated with significantly longer fusion time. This study evaluates the potential benefits of using a dynamically adjustable lens focus in future designs of HMDs.

[1]  Alexei A. Goon,et al.  Multifocal planes head-mounted displays. , 2000, Applied optics.

[2]  Anselmo Lastra,et al.  Combining Head-Mounted and Projector-Based Displays for Surgical Training , 2004, Presence: Teleoperators & Virtual Environments.

[3]  Mtm Marc Lambooij,et al.  Visual Discomfort and Visual Fatigue of Stereoscopic Displays: A Review , 2009 .

[4]  J. Rolland,et al.  Head-worn displays: a review , 2006, Journal of Display Technology.

[5]  David M. Hoffman,et al.  Vergence-accommodation conflicts hinder visual performance and cause visual fatigue. , 2008, Journal of vision.

[6]  D. Pickwell.  Binocular Vision Anomalies: Investigation and Treatment , 1984 .

[7]  James E. Melzer,et al.  Head-mounted displays , 1996 .

[8]  Richard H. Y. So,et al.  The Effects of Matching Lens Focus with Stereoscopic Depth Cues when Viewing Images Presented on a Head-Mounted Display , 2007 .

[9]  Colin Ware,et al.  Dynamic adjustment of stereo display parameters , 1998, IEEE Trans. Syst. Man Cybern. Part A.

[10]  James S Wolffsohn,et al.  The relationship between CA/C ratio and individual differences in dynamic accommodative responses while viewing stereoscopic images. , 2009, Journal of vision.

[11]  K. Ciuffreda,et al.  Effect of age on the interaction between the AC/A and CA/C ratios. , 1995, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[12]  Byron J. Pierce,et al.  Perceptual Issues in the Use of Head-Mounted Visual Displays , 2006, Hum. Factors.

[13]  D A Atchison,et al.  Accommodation-convergence relationships and age. , 1995, Investigative ophthalmology & visual science.

[14]  S K Rushton,et al.  Developing visual systems and exposure to virtual reality and stereo displays: some concerns and speculations about the demands on accommodation and vergence. , 1999, Applied ergonomics.

[15]  John Semmlow,et al.  Dynamic accommodative vergence components in binocular vision , 1976, Vision Research.

[16]  Ronald R. Mourant,et al.  Human Factors Issues in Virtual Environments: A Review of the Literature , 1998, Presence.

[17]  R. So,et al.  Cybersickness in the presence of scene rotational movements along different axes. , 2001, Applied ergonomics.

[18]  G. Hung,et al.  Convergence and Divergence Exhibit Different Response Characteristics to Symmetric Stimuli , 1997, Vision Research.

[19]  Caitlin Akai,et al.  Depth perception in real and virtual environments: An exploration of individual differences , 2007 .

[20]  M. Mon-Williams,et al.  Health issues with virtual reality displays: what we do know and what we don't , 1997, COMG.

[21]  Alan H. Tunnacliffe.  Introduction to Visual Optics , 1984 .

[22]  Mark Mon-Williams,et al.  Natural problems for stereoscopic depth perception in virtual environments , 1995, Vision Research.

[23]  Ronald S. Harwerth,et al.  Precision of stereoscopic depth perception from double images , 1993, Vision Research.

[24]  Fergal Shevlin.  A fixed-viewpoint volumetric stereoscopic 3D display using adaptive optics , 2005, IS&T/SPIE Electronic Imaging.

[25]  Martin S. Banks,et al.  A stereo display prototype with multiple focal distances , 2004, SIGGRAPH 2004.

[26]  L. Lipton.  Foundations of the Stereoscopic Cinema , 1982 .

[27]  B. Hendriks,et al.  Electrowetting-Based Variable-Focus Lens for Miniature Systems , 2005 .

[28]  V. V. Krishnan,et al.  A Heuristic Model for the Human Vergence Eye Movement System , 1977, IEEE Transactions on Biomedical Engineering.

[29]  Sumio Yano,et al.  Visual fatigue caused by stereoscopic images and the search for the requirement to prevent them: A review , 2012, Displays.

[30]  Sara McMains,et al.  Displaying readable object-space text in a head tracked, stereoscopic virtual environment , 2005 .

[31]  Nobuyuki Miyake,et al.  Development of stereoscopic 3D display system with dynamic optical correction , 2004 .

[32]  Hiroyasu Ujike,et al.  Visually induced motion sickness, visual stress and photosensitive epileptic seizures: what do they have in common? - preface to the special issue. , 2010, Applied ergonomics.

[33]  Jesse B. Eichenlaub.  Passive method of eliminating accommodation/convergence disparity in stereoscopic head-mounted displays , 2005, IS&T/SPIE Electronic Imaging.