Four generations /956 1st generation eye-in-head measurement,such as scleral (contact lens(隐形眼镜)/search coil,electro--oculography(EOG) 2nd generation photo-and video-oculography(眼震/眼动) -3rd generation analog video-based combined pupil/corneal()reflection (模拟/基于胶片的视频/电影的反射光记录) 4th generation digital video-based combined pupil/corneal reflection.Four generations  1st generation eye-in-head measurement, such as scleral (巩膜) contact lens(隐形眼镜) / search coil, electro-oculography(EOG )  2nd generation photo- and video-oculography (眼震/眼动)  3rd generation analog video-based combined pupil/corneal (角膜 ) reflection (模拟 /基于胶片的视频 /电影的反射光记录 )  4th generation digital video-based combined pupil/corneal reflection