Chris Rorden's Eye Movements Eye Monitors Infra-Red Oculography IR lights illuminate the lower portion of the pupil.
Sensors measure the reflected light.
Eye movements cause a different amount of light to be reflected on the sensors. These systems are low cost, portable, and are great for measuring horizontal saccade latency. Inexpensive, portable and offer good temporal resolution. However, these designs have a poor vertical signal and requires chin rest. Remote video imaging The eye is illuminated with infrared lights.