[Voltbishop]

I'd recommend the two products:

1. http://www.quha.com/products-2/accessories/quha-pufo/

It's a bluetooth device that allows controlling the mouse cursor with body movement (head or finger etc) It's cheaper. Coupled with a free dwell clicking software, should work!

2. Eye tracker - there are a lot of options, visit reddit.com/r/eyetracking that and reddit.com/r/ALS and ask them for advice. These devices let you control a PC with your eyes are especially designed for people who have ALS. The ones that work really well cost money, but most insurance companies cover them in full. Avoid Tobii, they are not reliable and are more marketing than anything. Mygaze,LC Technologies, Eyetech digital, smi vision. These are all companies you can trust. All should offer free trail periods and should have a rep who can come and visit your dad to do an evaluation. If they don't offer at minimum 2 week trail, they're not a trusted company. Secondly you can contact your local cities AT clinic they have donated equipment for situations like this.

I hope this helps!