To identify an object in the scene, the eyes move in conjugate fashion so that the image of the object falls on the fovea. Saccadic eye movements are the rapid shifts of gaze that redirect the visual axis onto a new point in the image. Foveation of an object often precedes further action directed at the object such as reaching and grasping. A network of neurons in the brainstem is responsible for generating the activation of ocular motor neurons necessary to produce these forces. The brainstem network is controlled by a network of oculomotor structures including the superior colliculus, a circuit through the basal ganglia, specific thalamic nuclei and particular areas of the cerebral cortex.
Infrared light is reflected off the border between the sclera and the iris.
The amount of reflected light is proportional to the relative amounts of iris and sclera in the beam which changes with eye position. The signal also reflects eye blinks. The two eye trackers can send output signals to more than one computer. The instructor and TA will each assist with one of the systems. You will need to develop a SuperScope II application to collect and save the data.