here are a few links about assistive technology-

http://www.eyegaze.com/2Products/Dis...bilitymain.htm
http://www.cs.bc.edu/~eagleeye/paper...r1/paper1.html
http://www.naturalpoint.com/smartnav..._overview.html
http://www.abilityhub.com/keyboard/eyegaze.htm

theres' probably more out there but this is a good start