Abstract
Purpose :
MD or a simulation of it induces an adaptive eye behaviour to compensate central visual loss: eccentric viewing. Extended reality (XR) tools are currently presented binocularly to assist eccentric viewing. Recent studies showed effective assistance of eccentric viewing behaviour with monocular peripheral assistance. How monocular and binocular peripheral augmentations affect eccentric viewing is unknown.
Methods :
Participants played a 2D Pong game in virtual reality (VR) requiring tracking a 3° moving ball. A circular scotoma was gaze-contingently simulated, and it covered 12° of the central visual field. Five different augmentations were concentrically applied at 7.5° away from the simulated scotoma’s edges. A 2° broad black ring, an area of 7.5° diameter, either blurred in or out were applied monocularly to the dominant eye. Zoom and fisheye distortions strategies were applied binocularly. Six participants were tested for each augmentation type in three different conditions: control, assisted scotoma, and scotoma simulation. For every condition, the median gaze-target distance was calculated. Kruskal–Wallis and post-hoc Dunn-Šidák tests were used to investigate the effect of condition type over median gaze-target distance. Polar histograms were used to analyse gaze directionality.
Results :
All peripheral augmentations tested induced a significant change in gaze-target distance between conditions (ring: χ2 (2) = 11.47, p = 0.003; blur-out: χ2 (2) = 8.43, p = 0.01; blur-in: χ2 (2) = 8.22, p = 0.02; zoom: χ2 (2) = 11.94, p = 0.003; fisheye: χ2 (2) = 8.29, p = 0.02). The post-hoc Dunn revealed that the scotoma condition was significantly different from the normal condition when presented after the ring (p=0.006), blur-out (p=0.01), blur-in (0.01), zoom, (p=0.003), and the fisheye (p=0.01) augmentation. Only after the monocular augmentations, the target was always kept visible throughout all blocks during the scotoma condition. Polar histograms indicated an upwards gaze-directionality for the ring and the zoom. Both monocular blurring augmentations had a back-and-forth strategy between the upper left and right hemisphere (Table 1).
Conclusions :
Monocular or binocular peripheral assistance differently influenced the eccentric gaze-behaviour of simulated MD participants. Blurring and ring augmentations seem to better improve eccentric viewing over magnification ones, even when applied monocularly.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.