For pupil dialations, you could also use Set Driven Keys for that
Simply make the lights' manipulator the driver, and key its' translation so that as it approaches the eye, the ramp, (or whatever pupil set-up you have), will get smaller.
Thus, your pupil dialtes to a pre-set max the farther away the light manipulator gets.
Another way would be to use the lights' intensity curve as the driver.
Otherwise, if it is just a one-off shot, you could just key the dialation also
Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS