Hermann Grid

• A Hermann Grid is an optical illusion.
  • Ludimar Hermann was a German physiologist.
  • While reading a book on sound by John Tyndall, Hermann saw gray spots in the intersections of spaces among the figures in the book.

• Viewers respond to what they see instead of what is actually there.
  • The viewer is the producer of meaning in the story.

• The illusion occurs because of the way retinal receptive fields respond.
  • Receptive fields in the central fovea are much smaller than in the rest of the retina.
    • The fovea is a specialized area of the retina with the most acute vision.

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© 2005 - 2008 John Michael Pierobon

Notes