light reflex

n.
  1. Contraction of the pupil of the eye in response to an increase in light.
  2. A circular red light reflected from the retina of the eye.red reflex
  3. cone of light
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.