Addressing the eye-fixation problem in gaze tracking for human computer interface using the Vestibulo-ocular Reflex

TL;DR

This paper presents a head-mounted gaze tracking system that leverages the Vestibulo-ocular Reflex to improve cursor control accuracy by focusing on smooth eye movements rather than saccades.

Contribution

The study introduces a novel gaze tracking method based on smooth eye movements, demonstrating significantly higher accuracy than traditional saccadic tracking in a human-computer interface.

Findings

Smooth eye movement tracking was four times more accurate than saccadic tracking.

Users could accurately place the cursor within a 9x9 pixel target 90% of the time using smooth movements.

Tracking smooth eye movements took longer (6.45 s) compared to saccadic movements (2.61 s).

Abstract

A custom head-mounted system to track smooth eye movements for control of a mouse cursor is implemented and evaluated. The system comprises a head-mounted infrared camera, an infrared light source, and a computer. Software-based image processing techniques, implemented in Microsoft Visual Studio, OpenCV, and Pupil, detect the pupil position and direction of pupil movement in near real-time. The identified direction is used to determine the desired positioning of the cursor, and the cursor moves towards the target. Two users participated in three tests to quantify the differences between incremental tracking of smooth eye movement resulting from the Vestibulo-ocular Reflex versus step-change tracking of saccadic eye movement. Tracking smooth eye movements was four times more accurate than tracking saccadic eye movements, with an average position resolution of 0.80 cm away from the target. In contrast, tracking saccadic eye movements was measured with an average position resolution of 3.21 cm. Using the incremental tracking of smooth eye movements, the user was able to place the cursor within a target as small as a 9 x 9 pixel square 90 % of the time. However, when using the step change tracking of saccadic eye movements, the user was unable to position the cursor within the 9 x 9 pixel target. The average time for the incremental tracking of smooth eye movements to track a target was 6.45 s, whereas for the step change tracking of saccadic eye movements, it was 2.61 s.