I am willing to bet that if these people <i>didn't</i> have some understanding of how the kinect works, they would not be experiencing this. Kind of similar to how small towns will occasionally complain about radiation from newly installed cell-towers, only to later realize the tower hasn't even been powered up yet.<p>As I understand the kinect's operation, it sends out a grid of dots, each dot being spread out by a few inches or so by a few feet away. In order to get a grid after-image, <i>assuming that IR could do that</i>, you'd have to be inches away from the device so that several different beams were all entering your eye through your pupil.<p>Now, it's possible there is something actually going on here, but my money is on psychosomatic. Seems <i>way</i> more plausible to me.