Eye trace is a editing technique to direct the viewers eye across consecutive shots. A classic example of eye trace would be an arrow shot from left to right. The viewers eye is tracking the arrow through the frame from the left to the right side and anticipates an impact from the arrow on the right side in the next shot. Lighting doesn’t have much of an influence in this eye trace scenario except to make sure the viewer gets a clear read of the arrow in both shots.
There are other eye trace situation though in which lighting plays a more important role e.g. to keep the viewers eye in the same region of the screen at the last frame of one shot and the first frame at the next shot. Like in the two shots below from Cinematographer: Roger Deakins in ‘Skyfall’.
The first shot of this edit(interior shot) directs the viewers eyes, with the help of bright light hitting the wall and the cabinet, to where the viewer should look at the first frame of exterior shot.
‘Eye trace’ example from the movie Drive. Cinematographer: Newton Thomas Sigel
At the end of the first shot the desk lamp next to the bed on the screen left side draws the viewers attention to this area. Cutting to the next show the viewers eyes is in the screen left region where the door opens.
Eye trace in CG:
Creating ‘lighting based eye trace’ in cg has the great advantage that by the time lighting starts a edited version of the sequence most likely already exists. Which makes it a lot easier to determine if eye trace is needed as well as if it can be achieved with the given layout. View the shot in context with surrounding shots helps to understand where the viewers eyes are in the shot before and after.