Residual gaze behaviour during navigation in blindness and low vision

Area of Science:

• Ophthalmology
• Human-Computer Interaction
• Rehabilitation Science

Background:

• Outdoor navigation presents challenges for individuals with blindness or low vision.
• Gaze behavior's role in mobility for visually impaired individuals is underexplored.
• Sighted individuals use consistent scanning, while visually impaired individuals adapt based on residual vision and experience.

Purpose of the Study:

• To comparatively analyze gaze behavior during outdoor navigation across different vision groups.
• To quantify differences in eye-tracking metrics and walking speed related to vision impairment.
• To understand how gaze strategies adapt to varying levels of visual acuity and impairment.

Main Methods:

• A comparative eye-tracking study was conducted with sighted, low vision, blind, and fully blind participants.
• Wearable eye trackers were used to quantify fixation counts, rate, area, direction, peak location, and walking speed.
• Participants navigated outdoor routes to simulate real-world mobility challenges.

Main Results:

• Walking speed decreased systematically with increasing vision loss.
• Fixation counts increased with impairment, indicating slower navigation and more frequent visual sampling.
• Fixation spatial coverage and consistency decreased with vision loss, with peak fixation shifting outward and becoming more variable.

Conclusions:

• Gaze strategies during navigation form a continuum across vision groups, from sighted to blind.
• Visual acuity alone doesn't predict gaze use; rehabilitation and adaptive strategies are key.
• Personalized rehabilitation and assistive technologies are needed, leveraging residual gaze patterns for safer navigation.