This is the homepage of the OMG Gazetracker. The project is still very much under work.
Here's a demonstration video showing the performance of the tracker in various environments.
For a description of the system, please refer to:
Kristian Lukander, Sharman Jagadeesan, Huageng Chi, and Kiti Müller. 2013. OMG!: a new robust, wearable and affordable open source mobile gaze tracker. In Proceedings of the 15th international conference on Human-computer interaction with mobile devices and services (MobileHCI '13). ACM, New York, NY, USA, 408-411. DOI=10.1145/2493190.2493214 http://dx.doi.org/10.1145/2493190.2493214
If you're interested, you can access the source code for the tracker, but be warned:
the installation is very complex, and only works under Linux systems.