Page 145 - Handbook of Electronic Assistive Technology

Chapter 5 • Alternative Access Technologies 133

using eye-gaze to control technology is quite a different task. Consequently, novice eye-
gaze users require high levels of concentration, many users experience fatigue and learn-
ing to use eye-gaze efficiently can take time (Donegan, 2012; Borgestig et al., 2016).
Eye-gaze technology has been researched as a control interface for people with dis-
abilities for many years (Majaranta and Räihä, 2002) and began to become available and
affordable from about 2004, when systems such as the Tobii P10 (Tobii Dynavox, 2015)
were launched. Since then, the utility of eye-gaze systems in assistive technology has
developed rapidly, and the cost has fallen dramatically. Systems are now available from
several manufacturers, including Tobii Dynavox, Alea (Alea Technologies, 2017) and Visual
Interaction (Visual Interaction, 2017). Consequently, eye-gaze access is becoming a more
commonplace method of assistive technology (Päivi, 2011).
Eye-gaze technologies are used in other fields such as the study of human–computer
interaction, gaming, marketing and consumer research, sports research and virtual reality.
Eye-gaze technologies are likely to become a mainstream method of interaction for con-
sumer electronics in the near future.
Eye-gaze access systems are arguably more technically complex to configure, learn and
use than, for example, a pointing device such as a mouse or trackball. With eye-gaze, the
system must be located at an appropriate distance and height relative to the user, the sys-
tem must be calibrated to the user and the user must learn how to use gaze to interact with
the screen and the device. Learning to use eye-gaze effectively requires time and practice,
and support from assistants and carers.

Eye-Gaze Technology
An eye-gaze access system consists of a camera unit that tracks the reflection of transmit-
ted infrared light from the user’s retina(s). The camera determines the direction of gaze
and calculates the precise location of gaze on the device screen. Eye-gaze cameras connect
to the assistive technology device via USB, and currently not available for iOS devices. Eye-
gaze cameras are available as standalone devices or built into dedicated communication
aids (Fig. 5-20).
To click or select using the eye-gaze camera, the user either rests the gaze on the item
for a set time, uses a ‘blink’ or activates a separate switch.

Assistive Technology Eye-Gaze Systems

Eye-gaze systems are available integrated into a complete dedicated device such as a voice
output communication aid. In addition, they are also available as separate camera units
with software and can be attached and installed on a computer, laptop and tablet, e.g.,
30
31
Tobii PC Eye Mini (Fig. 5-21) and myGaze Assistive 2 (Fig. 5-22). These units are light-
weight and small, easily transported and attached to computers using USB ports.

30 https://www.tobiidynavox.com.
31 http://www.mygaze.com.