Fig. 7 Basic closed-loop block diagram of the FEM mode of the version subsystem (heavy lines) superimposed on the block diagram of the total ocular motor control system. The control signal, conjugate retinal error, is sent to the cortex, and the decision to reposition the eyes is forwarded to the paramedian reticular formation of the pons where the motor commands are generated and passed on to the ocular motor nuclei (OMN). This innervation causes the extraocular muscles (EOM) to move the eye with an FEM and thus change relative eye position (REL. EYE POS.). Assuming no change in head position, the relative position constitutes the absolute eye position (ABS. EYE POS.), which summates with the target position at the retina to produce zero retinal error.