I'm trying to realize a tool that returns the 2D coordinates of the point that the user is looking at. To do that I'm using openCV, c++ language and a low-cost webcam. I have the 2D coordinates of the center of the two pupils (leftPupil, rightPupil) but I don't know how to find the user's gaze. I suppose that some information is missing but I don't know the right formula to estimate the gaze.
Is it mandatory to add a laser to get the distance of the user from the webcam? Must I analyze the geometric form of the pupil (if they are circles or elipses)? In this case, how can I detect the case in which they are eliptic or round?
Thank your for your ideas