Tobii https://gaming.tobii.com/product/eye-tracker-5/ is standard in consumer eye tracking, they even have integration with some popular video games! There's just no value in it. I tried an older version in a store, and it was basically perfect, tracking my eye's movements exactly, with zero delay.

Nobody wants it for day to day computer interaction. Most people using eye tracking for computer interaction are disabled, because it's a terrible experience.