quite a few folks in the voice programing community supplement voice commands with eye tracking using dedicated hardware. Talon [1] is considered an excellent resource in that field and there are also people in the Caster/dragonfly[2] ecosystem using EyeXMouse [3] and wolfmanstout [4] also has some work worth checking out.

[1] https://talonvoice.com/

[2] https://github.com/dictation-toolbox/Caster

[2] https://github.com/Versatilus/EyeXMouse

[4] https://handsfreecoding.org/2014/11/16/getting-started-with-...