I don’t know, but I DO know that if you are using the eyetracking for things where you can see the mouse and are trying to be accurate it INCREASES eye strain a LOT.
Tasks that use your gaze without you trying to pinpoint a location (like a tooltip that pops up if it notices you’ve been looking at something) should cause little to no strain on your eyes.
I would treat it like a muscle, and limit your daily time doing pinpoint accurate controls until you become more accustomed.
My first time eye-tracking I played solitaire for only like an hour, but I was clicking using blinks and controlling everything with my eyes. My head hurt and my eyes were tired afterwards, but I’m told you get better at it.