Human visual accommodation and vergence eye movement while viewing stereoscopic display and actual target

It is suggested that when viewing a binocular stereoscopic display (3D) there may be an imbalance between visual accommodation and vergence eye movement due to that the viewing distance is independent of the intersection point of the lines of gaze. To test this the authors measured visual accommodation and vergence eye movement while stimulating parallax-barrier stereoscopic display conditions. These results were compared with measurements using actual LED targets. Vergence is stable with both conditions. Although accommodative response when stimulated with a stereoscopic display revealed a large overshoot and unstable fluctuations, accommodation is stable when using an actual target. These results suggest that the instability of accommodation shown in the stereoscopic display is due to cross-coupling between accommodation and vergence