Ocular vergences measurement in virtual reality: A pilot study.

In this study, we investigated the value of using virtual reality to evaluate ocular vergence performance. We used a virtual reality device with an integrated eye-tracking system to create virtual environments that simulated far and near vision conditions and assessed ocular movements. We compared the maximum angular deviation compensated by the visual system or the vergence scores of the participants in the virtual environments with the vergence scores obtained with a prism in real environment, i.e. with the technique usually used for clinical assessments. We also compared a simple virtual environment with a complex virtual environment by creating landscapes. The vergence scores obtained for divergence and convergence with the virtual reality device were very similar to those obtained using prisms. This suggests that the virtual environments efficiently stimulated vision conditions in 3 dimensions. Our results also support the idea that modulating the angular deviation of the projected image in the virtual reality headset is a satisfactory way of inducing ocular vergences. The amplitudes of fusion were better in the virtual conditions, suggesting that the controlled virtual environments provided better conditions for measuring vergence movements. Furthermore, the virtual reality device induced a better amplitude of fusion in participants with high convergence abilities by preventing the underestimation of divergence abilities in these participants. This last result suggests that this type of virtual reality mechanism could be helpful in the future for remediating vergences-related disorders.