title: Psychological and other mechanisms for end-of-day soft lens symptoms.
abstract: OBJECTIVE
  To examine psychological factors and other mechanisms for soft contact lens (CL)-related end-of-day symptoms of dryness and associated dropping out from lens wear.
  
  
  METHODS
  A PubMed search for articles related to dryness, comfort, and discomfort in CLs was conducted. Comparisons with rigid lens adaptation have been used to construct and examine a hypothesis that high levels of initial soft lens comfort increase expectations of an absence of lens awareness that result in end-of-day symptoms being more difficult to tolerate.
  
  
  RESULTS
  Relevant reports were referenced in this review having been located using the 143 listed by PubMed. Contact lens-induced corneal hypoalgesia and the association between the influence on blink function of end-of-day general and ocular fatigue, lens front surface degradation, a dysfunctional pre-lens tear layer, and symptoms of dryness suggest that lid wiper friction has a prime role in determining the level of lens awareness.
  
  
  CONCLUSIONS
  Rather than dry eye symptoms, end-of-day discomfort in CL wearers might be more appropriately described as dry lens symptoms. Apart from tear function, lens condition, compliance with lens care instructions, and symptom strength, lens awareness may also be determined by psychological factors such as motivation, high expectations for comfort, and sense of subjective well-being. For example, high levels of comfort experienced on lens insertion may increase expectations of the level of comfort to be experienced at the end of the day. In addition, patient management seems to require a thorough assessment of lens comfort, which may indicate the need to review a patient's understanding of the relation between compliance and other factors, which could influence CL performance negatively. For example, increased use of digital devices, especially in air conditioning, and any associated reduced blink efficiency seem likely to be important contributors to dry lens symptoms.
authors.affiliation: School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia. c.mcmonnies@unsw.edu.au
authors.forename: Charles W
authors.initials: CW
authors.lastname: McMonnies
mesh_terms: D000223:Adaptation, Psychological; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects / Q000523:psychology*; D015352:Dry Eye Syndromes / Q000209:etiology / Q000378:metabolism / Q000523:psychology*; D006801:Humans; D010349:Patient Compliance; D010352:Patient Dropouts; D013666:Tears / Q000378:metabolism