Disparity vergence dynamics during 3D viewing are influenced by ocular rigidty

Conference Paper

2013

Published in: https://cdn.evbuc.com/eventlogos/5731889/bcovsabb..pdf

Alhazmi, Mohammed . 2013

Purpose: To determine the effect of eye size and ocular rigidity upon the characteristics of disparity vergence eye movements under 3D viewing conditions.

Methods: 30 subjects (mean age ± SD of 26.56±4.66years) with normal binocular vision and VA of 6/6 or better participated with informed consent in the study. Axial length (24.16±1.40mm) was measured using partial coherence interferometry (IOLMaster, Carl Zeiss, UK). Ocular rigidity coefficients (0.0160±0.002) were determined using Schiotz tonometry. Subjects viewed a high contrast Maltese cross for 5 minutes presented on a 3D LCD display (LG Electronics; 1920x1080pixels) at a distance of 2m.  Disparity vergence varied sinusoidally at temporal frequencies of 0.05, 0.1, 0.3, 0.5 and 0.7 Hz and amplitudes of 0.8, 3 and 6 degrees. Eye movements were recorded continuously at a sampling rate of 100 Hz using the IRIS Simulink eyetracker (Skalar Medical B.V. The Netherlands). For data analysis subjects were divided into 3 equal groups according to their ocular rigidity.

Results: Response gain was significantly higher for the crossed disparity stimulus, (p<0.001) although these responses showed significantly higher phase lag (p=0.028) compared to uncrossed disparity. Response gain decreased and phase lag increased significantly over time as subjects viewed the stimulus (p<0.001). This effect was significantly greater for subjects with lower ocular rigidity (p<0.001). Response gain reduced and phase lag increased with increasing stimulus amplitude (p<0.001). Increasing the stimulus frequency significantly decreased the response gain and increased the phase lag (p<0.001). Ocular rigidity and axial length were significantly negatively correlated (r2=0.76, p<0.001).

Conclusion: The sinusoidal disparity vergence response deteriorates in quality after very short viewing times for 3D presentation. This deterioration in response appears to be exacerbated in larger eyes with lower ocular rigidity. These results suggest that stereoscopic displays may present a more challenging environment for subjects with larger eyes and/or lower ocular rigidity.

• Publication Work Type: Conference Poster
• Conference Name: British Congress of Vision Science (BCOVS),
• Sponsoring Organization: Glasgow Caledonian University