title: What is dry eye and what does it mean to the contact lens wearer?
abstract: OBJECTIVE
  To define dry eye disease and describe the evolution of our understanding of the clinical expression and pathophysiology of dry eye. To relate tear function to contact lens wear and review the problems dry eye causes with contact lens tolerance and performance.
  
  
  METHODS
  Review of literature.
  
  
  RESULTS
  The rudimentary definition of dry eye as a lack of tears is expanded through an increased understanding of the clinical presentations of dry eye. The classification of dry eye is historically reviewed. The pathophysiology is related to the evolution of therapy for dry eye disorders. The function of the tear film is related to contact lens wear and the problems induced by dry eye correlated with contact lens intolerance.
  
  
  CONCLUSIONS
  The tear film is critical to successful contact lens wear. Disturbances of the quantity or quality of the tear film, whether because of aqueous deficiency or evaporative tear problems, results in intolerance of contact lens wear and damage to the ocular surface.
authors.affiliation: Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. foulksgn@msx.upmc.edu
authors.forename: Gary N
authors.initials: GN
authors.lastname: Foulks
mesh_terms: D003261:Contact Lenses; D015352:Dry Eye Syndromes / Q000503:physiopathology; D006801:Humans; D013666:Tears / Q000502:physiology