Want to know the user's gazing point on the computer monitor?

For that i have developed an Eye Tracking System. Using this system we can identify the user's gazing point on the computer monitor. This system mainly has four light resources mounted on four corners of the monitor and a web camera. Four light resources are for keeping the track of monitor margins and the web camera for record user's actions.
To calculate the user's gazing point coordinates i have used the coordinates of four light reflected points on the eye and the coordinate of center of eye pupil.
I have used C#, C++ and OpenCV Image Processing Library which has developed by Intel to code this system.
These are some of my systems screen shots.
Feel free to publish your comments.
Thanks.