A Switching Process Controls Dual Mode Accommodation Responses To Ramp Inputs: Experimental And Modeling Evidence

The staircase appearance of the accommodation response to a ramp stimulus, slow movement of the target toward the subject's eye, leads to notions of switching between two control modes. Experiments and model simulations indicate that blur processing by retina-and-cortex underlies threshold triggering of the switch. The ON mode consists of a fairly high-gain closed-loop minimizing error. The OFF mode provides for quasi-open loop state, and a slow driftt to a bias level under influence of a leaky integrator.