glaucomatous halo

n.
  1. A yellowish ring surrounding the optic disk, indicating atrophy of the choroid in glaucoma.
  2. A circle of illumination seen around lights, caused by corneal edema in glaucoma.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.