The recent ABC science program, Catalyst, featured a new invention by Dr Jordan Nguyen. It demonstrated how a 13 year old boy living with cerebral palsy could use his eyes to directly control the lights, the fan and the television. Various environmental control systems designed for people with disability have been commercially available for many years, but these often require the use of a tablet or computer. Occupational therapists and bio-medical/rehabilitation engineers can skillfully adapt existing devices to suit individual needs.
Research on eye-tracking or eye-gaze systems is going on all the time and David Hobbs and his team at Flinders University are at the forefront of such inventions and adaptations. For those interested in some of the background to these systems, you can download their most recent publication on using low cost, portable, tablet-based systems for children.
Spectronics Australia has a catalogue of assistive technologies for children with disability, including devices using eye-gaze techniques.