APA Dictionary of Psychology

the components of the nervous system and the nonneural apparatus of the eye that contribute to the perception of visual stimulation. The anterior structures of the eye, such as the cornea and lens, focus light on the retina, which transduces photons into neural signals. These are transmitted via the optic nerve and optic tract to nuclei in the thalamus and brainstem. These in turn transmit the signals either to the visual areas of the cerebral cortex for hierarchical processing and conscious analysis or directly to motor centers in the brainstem and spinal cord to produce eye movements.