For people experiencing severe motor impairments, simple devices like mouth sticks or head wands don't remove roadblocks that prevent users from navigating the screen. In turn, eye-tracking devices can be a powerful alternative. They allow individuals with disabilities to navigate their computer or mobile devices with only eye movements.

Specifically, to use the device from the example, you should connect it via USB to your computer and stick the metallic mount to the bottom of your monitor. The device is very flexible and doesn't require you to sit still. Its sensors catch your eyes even when you're moving your head.

Sometimes, eye-tracking systems may include word-completion tools, so users can generate speech faster by typing or choosing from suggested phrases. Naturally, such sophisticated devices are more expensive and less common.

Image credit: Tobii Pro

Image credit: NS Medical Devices