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2. Pedestrian Collision Detection and Avoidance in Cerebral Visual Impairment During Unrestricted Walking in an Immersive Virtual Reality Environment

 # Pedestrian Collision Detection and Avoidance in Cerebral Visual Impairment During Unrestricted Walking in an Immersive Virtual Reality Environment

  ![Publication image](/sites/default/files/styles/wide/public/default_images/default.jpeg?itok=TfIobf92 "Publication image")

 Walking safely through highly crowded environments is a significant challenge for individuals with cerebral visual impairment (CVI). Yet current ophthalmic examinations do not capture functional visual difficulties related to safe mobility. We developed an immersive virtual reality (VR)-based task that tracked eye gaze behaviors within dynamic areas of interest to assess pedestrian collision detection, avoidance, and associated visual scanning in CVI (n=12) compared to control (n=14) participants. Subjects walked through a simulated shopping mall populated with crowds of varying densities. The testing scenario was presented using a head-mounted display with integrated eye tracking, and locomotor, behavioral, and visual scanning responses were recorded. Compared to controls, CVI participants exhibited a slower mean preferred walking speed. They were also less likely and slower to detect target (colliding) pedestrians and were more likely to make a collision. CVI participants were also slower in making their first fixation and followed a larger visual scan path to find the target pedestrian. They also spent more time fixating on non-target compared to target pedestrians. Finally, CVI participants showed greater variability in their performance (including pathing deviations), reflecting a range of individual strategies, and maintained a larger walking safety margin (spatio-temporal envelope). These results provide objective evidence of mobility and associated gaze behaviors in CVI during navigation through highly crowded environments.

 ## Authors

Jonathan Doyon (Harvard Medical School)

Madeleine Heynan (Harvard Medical School)

Wei Hay Lew (Harvard Medical School)

Alex D. Hwang (Harvard Medical School)

[Jae-Hyun Jung](/person/jae-hyun-jung)

Lotfi B. Merabet (Harvard Medical School)

 ## Publication Date

Monday, June 22, 2026

 ## Published in

[NIH PubMed Central](https://pmc.ncbi.nlm.nih.gov/articles/PMC13321285/)

 ## Research Area

[Applied Perception](/research-area/applied-perception)

[Human Computer Interaction](/research-area/human-computer-interaction)

[Medical](/research-area/medical)

[VR, AR and Display Technology](/research-area/virtual-augmented-reality)

[World Simulation](/research-area/world-simulation)