Related Experiment Video
Updated: May 16, 2026

A Standardized Obstacle Course for Assessment of Visual Function in Ultra Low Vision and Artificial Vision
Published on: February 11, 2014
Within reach but not so reachable: obstacles matter in visual perception of distances
Nicolas Morgado1, Edouard Gentaz, Eric Guinet
1Laboratoire de Psychologie et Neurocognition (CNRS), Université de Grenoble, Grenoble, France. nicolas.morgado@upmf-grenoble.fr
Abstract:
A large number of studies have shown that effort influences the visual perception of reaching distance. These studies have mainly focused on the effects of reach-relevant properties of the body and of the objects that people intend to reach. However, any influence of the reach-relevant properties of the surrounding environment remains still speculative. We investigated this topic in terms of the role of obstacle width in perceiving distances. Participants had to estimate the straight-line distance to a cylinder located just behind a transparent barrier of varying width. The results showed that participants perceived the straight-line distance to the cylinder as being longer when they intended to grasp the cylinder by reaching around a wide transparent barrier rather than by reaching around narrower ones. Interestingly, this effect might be due to the anticipated effort involved in reaching. Together, our results show that reach-relevant properties of the surrounding environment influence perceived distances, thereby supporting an embodied view of the visual perception of space.
Related Concept Videos
Depth Perception and Spatial Vision
Sight Distance in a Vertical Curve
Design Example: Measuring Distance Between Two Points with Obstructions
Gestalt Principles of Perception
Perceptual Constancy
Size constancy is the recognition that an object remains the same size, even when its image on the retina changes. For instance, a bus is perceived to be large enough to carry people, even if it looks tiny from...
Focusing of Light in the Eye

