The Organic Crystalline Materials of Vision: Structure–Function Considerations from the Nanometer to the Millimeter Scale

Benjamin A. Palmer, Dvir Gur, Steve Weiner, Lia Addadi, Dan Oron

Research output: Contribution to journalReview article

5 Citations (Scopus)


Vision mechanisms in animals, especially those living in water, are diverse. Many eyes have reflective elements that consist of multilayers of nanometer-sized crystalline plates, composed of organic molecules. The crystal multilayer assemblies owe their enhanced reflectivity to the high refractive indices of the crystals in preferred crystallographic directions. The high refractive indices are due to the molecular arrangements in their crystal structures. Herein, data regarding these difficult-to-characterize crystals are reviewed. This is followed by a discussion on the function of these crystalline assemblies, especially in visual systems whose anatomy has been well characterized under close to in vivo conditions. Three test cases are presented, and then the relations between the reflecting crystalline components and their functions, including the relations between molecular structure, crystal structure, and reflecting properties are discussed. Some of the underlying mechanisms are also discussed, and finally open questions in the field are identified.

Original languageEnglish
Article number1800006
JournalAdvanced Materials
Issue number41
Publication statusPublished - Oct 11 2018



  • crystals
  • eyes
  • guanine
  • reflection
  • vision

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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