title: Prescribing for the moderate-to-advanced ametropic presbyopic VDT user. A comparison of the Technica Progressive and Datalite CRT trifocal.
abstract: BACKGROUND
  Use of video display terminals (VDTs) is expected to dramatically increase. This clinical study was performed to examine the moderate-to-advanced ametropic presbyopic VDT user to determine the most prevalent visual or physical symptoms incurred while working at a VDT, and to develop a comparative benefit analysis of two currently available occupational lens designs.
  
  
  METHODS
  Twenty-four symptomatic VDT users who were currently wearing a non-occupational lens design were selected from a pool of 100 applicants. The non-occupational lens distribution included 17 bifocals, 3 trifocals and 4 progressives lenses. The subjects compared two occupational lens designs.
  
  
  RESULTS
  Statistical analyses indicated that the frequency and severity of seven of 10 symptoms reported were significantly reduced by wearing the occupational lenses, including the three most frequently reported pre-existing symptoms of neck/shoulder aches, eyestrain, and blurred intermediate vision.
  
  
  CONCLUSIONS
  Study results suggest that symptomatic moderate-to-advanced ametropic presbyopic VDT users may benefit from an occupational progressive lens when work involves prolonged or exclusive viewing of a VDT screen. An occupational trifocal may benefit VDT users also required to perform other viewing tasks.
authors.forename: S P
authors.initials: SP
authors.lastname: Butzon
authors.forename: S R
authors.initials: SR
authors.lastname: Eagels
mesh_terms: D000368:Aged; D016288:Computer Terminals; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D011305:Presbyopia / Q000209:etiology / Q000628:therapy*; D055656:Prescriptions; D011795:Surveys and Questionnaires