Dictionary.com
definitions

ciliary ganglion

n.
  1. A small parasympathetic ganglion in the orbit behind the eye that receives preganglionic innervation through the oculomotor nerve and gives rise to the postganglionic fibers that innervate the ciliary and sphincter muscles of the pupil.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.