since I don’t know exactly what your idea of interacting with Google Earth by eye-gaze is, I can just come up with a hand-wavy answer: try to filter the gaze point data, using for example a moving average filter, to get a smoother signal.
If you’re using the EyeX SDK then you can try the lightly filtered data stream instead of the unfiltered one. But the lightly filtered stream might still be too noisy for your needs. Finding the filter parameters that are just right can be difficult but it’s usually necessary for a good user experience.
It would be nice to see what you come up with. Maybe there are other developers out there as well that would benefit from a really smooth gaze data stream.