Essay On Eye Tracking

1.1. Introduction

Eye tracking systems are used to monitor eye movements and translate the user’s gaze direction into computer monitor coordinates. In other words, eye tracking is a methodology that helps researchers understand visual interest. With eye tracking, we can observe where users look at a point in time, how long they fixate on it, and the path their eyes pursue. Eye tracking has been applied to fields that include human factors, cognitive psychology, marketing, and the broad field of human–computer interaction. Especially for people with severe motor disabilities, gaze may be their only means of communicating or controlling their environment [a].

This chapter provides a brief summary of the previous research in this domain and a general idea of what eye tracking systems are. We will first have a quick glance into the history and applications of eye tracking, followed by a brief introduction to currently available eye tracking assistive devices, and close by introducing some common terms that repeatedly appear throughout this report.

1.2. Brief History

Early eye tracking systems were intended solely for studying the nature of human eye movements rather than for interaction [b], and were reserved for understanding the main theory of how the brain and the visual system worked together (Fig. 1.1). This study traces its origin to 1879,

Calibration usually requires individuals to look at an image set at a fixed known location. The eye-tracking system then evaluates the exact position of the image to where it perceives the person’s gaze on the screen, and administers a suitable rectification for future fixations. Drift adjustment calculates the amount of the dissimilarity between a user’s gaze and a vital point over a short interval. Drifts are very small random movements of the eye occurring due to fatigue or changes in head