Meaning of antireflection coating

an•ti•re•flec'tion coat"ing

Pronunciation: (an"tē-ri-flek'shun, an"tī-), [key]
— Optics.
  1. a thin film consisting of one or more layers of transparent material applied to lenses to reduce reflection.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.