分析了在人眼视线方向检测中普尔钦斑的成像机理，探讨了普尔钦斑的位置与眼球转动角度间的变化关系，发现普尔钦斑的位置随着眼球的转动而基本呈线性变化的规律。提出了仅利用普尔钦斑的偏移量来检测视线方向的新方法。该方法只需在拍摄得到的眼睛图像中寻找灰度特征明显的普尔钦斑即可准确判断出使用者的视线方向。实验证明，该方法简单有效，所需要的运算量小，可提高视线方向的检测速度和精度，能进一步简化检测装置。

The imaging principle of Purkinje image,the change of its position with the eye moves are analyzed,and the position of Purkinje image shifts linearly with the rotation-angle of eyeball is proposed. Based on this,a novel approach to non-intrusive gaze tracking,which only must locate the Purkinje image that has evident edge and prominent grey-scale in the captured eye-image to get the line of sight of a person,is proposed. The experiment validates its high speed and high accurate in gaze tracking,and thus can simplify the gaze tracking system.