Many communication aid systems have been developed for severely physically handicapped people like ALS patients. The eye-gaze input system is being studied as an interface for a communication aid that can operate a computer with eye movement alone. Conventional eye-gaze input systems, however, can harm users. This is due to the use of infrared rays on the eyes to detect the eye-gaze. The prolonged irradiation could potentially cause eye damage such as glassblower's cataract, retinitis solaris, or dry eyes. We propose an eye-gaze input system using a personal computer and a home video camera for eye-gaze detection under natural light. The system detects the eye-gaze using image analysis based on the limbus tracking method, and it does not require special image processing units or sensors. The system is safe, compact and easy to use.
