So, the think is i want to build a software who can track the possition of the pupil, but i cant find on internet a mathematical aproch to the problem. I want to see some examples of how to calculate the position of the pupil. Thanks!
I think the most common way involves illuminating the subject with a point light source and using the bright specular highlight on the cornea to locate the eyeball. Then the location of the pupil relative to the highlight gives you the direction. To simplify the image processing you use IR light and an IR monochrome camera.
To work out the math try sketching it in 2D with a circular "eyeball", a fixed point light that creates the specular highlight where a line between the light and the center of the eye crosses the circle, and a shaded arc to represent the pupil.