The head motion detection and compensation mechanisms significantly improve the final system precision/accuracy of a gaze tracker. But the problem becomes more difficult for a visible-spectrum gaze track compared with the one based on an infra-ray (IR) lighting system for the lack of the IR light sources as the reference locations. This paper presents a robust detection as well as a compensation mechanism for a visible-spectrum gaze tracker by using more stable feature points on the entire head image. The limbus circle matching module dynamically adjusts the eyeball model and calculates the moving distance of the head. The experimental results show that the compensation mechanism further improves the system performance of the gaze tracker when the user moves their head.