Doing it for free (ish)
Before we start I should point out that you need a webcam to accomplish this. I have used the word ‘free’ so liberally as most laptops these days seem to have a tiny webcam already built in to the top of the screen. If your computer doesn’t have a webcam then fear not as you can pick one up for as little as £5.
In addition to the webcam you need one small and wholly free piece of software called Camera Mouse. The software is easy to download, install and set up. The biggest difference between this software and the expensive options is that it won’t track as special dot and therefore sometimes tracks background items and can get confused and needs resetting. It’s a good backup, however, and can be used to demonstrate and assess for head pointer control.
You can use Camera Mouse with on-screen keyboards such as the free windows OSK or The Grid etc.