Complex spatial updating in simulated low vision

Critical to low vision navigation are the abilities to recover scale and update a three-dimensional representation of space. In order to investigate whether these abilities are present under low vision conditions, we employed the triangulation task of eyesclosed indirect walking to previously viewed targets on the ground. In experiment 1, we explored the feasibility of simulating low-vision more precisely using a novel material. In experiments 2 and 3, we investigated distance perception under normal vision and simulated low vision conditions. Visually directed walking measures, such as the direct and indirect walking tasks, can be used as a measure of absolute distance perception. The indirect walking task requires that the observer continually update the location of the target without any further visual feedback of his/her movement or the target's location. Normally sighted participants were tested monocularly in a degraded vision condition and a normal vision condition on both indirect and direct walking to previously viewed targets. Surprisingly, we found no difference in walked distances between the degraded and normal vision conditions. Our results provide evidence for intact spatial updating even under severely degraded vision conditions, indicating that participants can recover scale and update a three-dimensional representation of space under simulated low vision.