Hi @joostbos, thanks for your query. I assume you are referring to the gaze overlay feature within the Tobii System Tray Icon? I am afraid we do not expose any further settings for the size of the bubble at this time. The bubble size in fact reflects the area over which the eye gaze can be said to be present, which is a consequence of the eye-tracking algorithm we implement, not an arbitrary variable.
However, I have passed along your request to the developer for consideration into a future release.
Apologies for the inconvenience and hope you can work around the situation.