Robotics technology has been making many long overdue advances in artificial limbs that are finally affordable to the average person.
Even toy companys have been creating toy arms and hands in the last 10 years which has done wonders to make the average robotics hobbyist explore ways to create their own better versions of these hands.
(Thames & Kosmos, KidzRobtix, Mega Cyborg Hand)
There have even been advances where a $50,000 arm could be 3d printed on a simple 3d printer and assembled with the electronics for under a few thousand dollars.
Check out the amazing TED talk video of Hugh Herr who was an advanced rock climber who lost part of both legs and is now heading up major advances in advanced prosthetics.
https://www.news-medical.net/health/Recent-Advances-in-Robotic-Surgery.aspx
Quadraplegic patients and patients who have difficulty using a keyboard have been able for several years to use their own eye movements to control their computers for typing and computer use.
We may remember the famous physicist/scientist Steven Hawking as he would use his speech synthesis product and eye movements to control his keypad computer.
A company which has made great developments in eye tracking technology is EyeTech Digital at this address. https://www.youtube.com/watch?v=JBwxq0ZbPio
A smallish company involved in helping design products for those with various physical challenges is Rapadapt and is run by Devin Hamilton who has worked with his own cerebral palsy over his lifetime. Here is their website. http://www.rapadapt.com