Pupil Reflex

Involuntary action where the pupils constrict or dilate in response to changing light intensities

1. Light enters the eye and falls on the Retina
2. Retina sends impulse via Optic Nerve to the brain, and brain sends impulse to the iris muscles
3. When the light intensity is high:
   1. Circular muscles contract
   2. Radial muscles relax
   3. Pupil constricts
4. When the light intensity is low:
   1. Circular muscles relax
   2. Radial muscles contract
   3. Pupil dilates