The game "Conker's Bad Fur Day" for the Nintendo 64 boasts several special effects never seen before in that platform at the time, even featuring a rudimentary shadow-mapping effect.
One of the special effects of this game is especially intriguing. It occurs when you're using the "POV" camera mode to look around the level and happen to orbit around the character's face. His eyes follow the camera.
I've looked at the wireframe for the character mesh and noticed the character's eyes are entirely represented by texturing. They aren't "decal" meshes as one would expect. So the effect of movable eyes is somehow achieved by transforming the texture's matrix so as to make it slide.
Here's some footage from the game:
I was wondering what would be the math theory behind this, to compute an UV offset for an "eye" texture based on a point of origin (the position of the eye) and a point of destination in space (the object being looked at).