You can adjust gaze sensitivity, while search up puts the app on hold. Google says all Look to Speak data is private and stays on the device.
There has been other work to help people with speech and motor impairments use eye tracking to communicate. Microsoft has been working on a smartphone-based system called GazeSpeak while a video that explains Look to Speak shows a person writing a message using their gaze and an onscreen keyboard.
Look To Speak is part of Start with a project under the umbrella of experiments with Google. Recent experiences on this platform include a endless music video app filled with covers of Billie Eilish’s “Bad Guy”.