In laser eye surgery, success of operation is dependent to coherency of eye tracking system. In this paper, we present a method developed for eye tracking. Present methods generally use pupila and iris as a reference to detect changes in eye orientation. In some cases, these methods suffers due to movement of pupila. Our method uses scleral blood vessels as a reference to apply image registration. Thus, it has a potential to solve the problems in current methods. Our method's primary application is on eye treatment but it can be evaluated for other domains like human-computer interaction.