title: François Pourfour du Petit (1664-1741): pioneer in ocular biometry.
abstract: To outline the important contributions of the French physician Petit to the development of ocular biometry.
  
  
  
  After a brief review of Petit's life and his studies in neurology, anatomy, and cataract surgery, the methodology and results of his work in measuring many of the biometric parameters of the human eye are discussed. Among other techniques, he made use of frozen sections of eyes to explore their dimensions and employed an immersion technique to avoid the effect of corneal refraction on the appearance of the iris. His pioneering biometric results have been largely confirmed by modern studies. Those on the changes in the crystalline lens with age are particularly striking and suggest that these ocular aging effects have changed little over the last 300 years. Although largely forgotten today, his biometric work exercised a considerable influence on his more immediate successors, including Porterfield and Thomas Young.
  
  
  
  François Pourfour du Petit deserves to be remembered as an important contributor to our understanding of the structure and dimensions of the human eye.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, UK.
authors.forename: W Neil
authors.initials: WN
authors.lastname: Charman
mesh_terms: D001699:Biometry / Q000266:history*; D003941:Diagnostic Techniques, Ophthalmological / Q000266:history*; D005128:Eye Diseases / Q000175:diagnosis / Q000266:history*; D005602:France; D049670:History, 17th Century; D049671:History, 18th Century; D006801:Humans; D009885:Ophthalmology / Q000266:history*
keywords: Petit; age; corneal neutralisation; crystalline lens; ocular biometry; optometric history