In order to keep image-magnifying rate of optical system unchanged in eye-gaze human-computer interaction, automatic zoom is used to keep image size by motorized zoom lens and eye characteristic which is tracked based on image processing. 在视觉人机交互中,为实现光学系统成像放大率不变,采用电动变焦(MZ)镜头,基于图像处理跟踪人眼特征信息,自动变焦实现图像大小不变。