title: Field observations of display placement requirements and character size for presbyopic and prepresbyopic computer users.
abstract: BACKGROUND
  Computer users continue to report eye and upper body discomfort even as workstation flexibility has improved. Research shows a relationship between character size, viewing distance, and reading performance. Few reports exist regarding text height viewed under normal office work conditions and eye discomfort.
  
  
  OBJECTIVE
  This paper reports self-selected computer display placement, text characteristics, and subjective comfort for older and younger computer workers under real-world conditions.
  
  
  METHODS
  Computer workers were provided with monitors and adjustable display support(s). In Study 1, older workers wearing progressive-addition lenses (PALs) were observed. In study 2, older workers wearing multifocal lenses and younger workers were observed.
  
  
  RESULTS
  Workers wearing PALs experienced less eye and body discomfort with adjustable displays, and less eye and neck discomfort for text visual angles near or greater than ergonomic recommendations. Older workers wearing multifocal correction positioned displays much lower than younger workers. In general, computer users did not adjust character size to ensure that fovial images of text fell within the recommended range.
  
  
  CONCLUSIONS
  Ergonomic display placement recommendations should be different for computer users wearing multifocal correction for presbyopia. Ergonomic training should emphasize adjusting text size for user comfort.
authors.affiliation: Ergonomics R&D Program, Hewlett-Packard Company, Houston, TX, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Bartha
authors.affiliation: Kokot and Allie Associates, LLC, Grand Rapids, MI, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Allie
authors.affiliation: Kokot and Allie Associates, LLC, Grand Rapids, MI, USA.
authors.forename: Douglas
authors.initials: D
authors.lastname: Kokot
authors.affiliation: ROE Ergo R&D, LLC, The Woodlands, TX, USA.
authors.forename: Cynthia Purvis
authors.initials: CP
authors.lastname: Roe
mesh_terms: D000065:Accommodation, Ocular; D000328:Adult; D000367:Age Factors; D000368:Aged; D016288:Computer Terminals; D003626:Data Display; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000517:prevention & control; D011187:Posture; D011305:Presbyopia / Q000503:physiopathology / Q000628:therapy; D014792:Visual Acuity
keywords: Monitor placement; age-related vision impairments; display height; display tilt; text size