Another alternative to the mouse as a pointing device is to use a gaze-trackingcamera, which works out where you are looking and moves an on-screen pointer accordingly.
另外一种鼠标替换物是视线跟踪系统，它能判断出你的视线移动的位置并相应地调整屏幕光标移动的位置。
2
The digital photograph was made with a camera mounted on a telescope tracking the stars through dark skies above a camp ground in Virginia, USA.
这张数码照片是用架在能跟踪天体的望远镜上的照相机拍的，于美国弗吉尼亚一露营基地。
3
But the camera is actually tracking where my fingers are moving.