Walsh & Hoyt: Normal Pupillary Reflexes

When light is shined in either eye, both pupils constrict. The constriction in the ipsilateral eye is called the direct reaction to light and that in the contralateral eye is called the consensual reaction to light. For practical purposes, with unilateral light (as well as electric) stimulation, the direct and consensual reactions are of equal magnitude, provided that there is no lesion in the parasympathetic or sympathetic pathways. Reaction to light. Alternating contraction anisocoria. Effect of age on the pupillary light reflex. Role of the pupillary light reflex. Latent period of the pupillary light reflex. Effect of stimulus intensity on the pupillary light reflex. Spectral sensitivity of the pupillary light reflex. Pupillomotor sensitivity of the retina. Modification of the pupillary light reflex by emotion and fatigue. Binocular interactions of the pupillary light reflex. Conditioning of the pupillary light reflex. Pupillary light reflex as a servomechanism. Pupillary reaction to darkness. Pupillary reflex to near and the near response. Reflexes following eyelid closure. Reflex dilation.