title: Adjustable task lighting: Field study assesses the benefits in an office environment.
abstract: BACKGROUND
  Lighting is a part of every work task in the office environment, yet it is often overlooked. Research links direct and indirect glare to increased risk of visual discomfort among office workers with symptoms ranging from dry eyes to blurry vision or headaches. Researchers have been primarily concerned with those characteristics of task lighting that cause glare including luminance level, position (line of sight), and control. It is unknown what the benefits of adjustable task lights are and whether or not their use has an effect on musculoskeletal comfort or posture. No comprehensive field evaluations of this type were found among peer-reviewed, indexed journals.
  
  
  OBJECTIVE
  The purpose of this study was to assess the ergonomic and calculated utility power consumption benefits of adjustable LED task lighting in an office environment using a control/intervention experiment design.
  
  
  METHODS
  One hundred participants were originally recruited and randomly assigned to intervention and control groups. Self-reported data was collected on level of eye fatigue, perception of job content, intervention usability, and musculoskeletal discomfort. Data was also collected on workspace level of illumination and posture during standardized tasks (assessed using RULA).
  
  
  RESULTS
  Comparing baseline data to follow-up data for the intervention group, the use of the adjustable, LED task lights provided statistically significant, positive impacts on users' rating of discomfort, eye fatigue, perception of job content, and posture between baseline and the short-term follow up.
  
  
  CONCLUSIONS
  Significant benefits to musculoskeletal comfort, posture, and visual comfort were documented when participants used the adjustable task lights. Participants' assessments of the light's usability, usefulness and desirability were positive. There were no negative results found with adjustable task light use.
authors.affiliation: Industrial Design, College of Design, North Carolina State University, Raleigh, NC, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Joines
authors.affiliation: Ergonomics Division, Occupational & Environmental Safety, Duke University, Durham, NC, USA.
authors.forename: Tamara
authors.initials: T
authors.lastname: James
authors.affiliation: Industrial Design, College of Design, North Carolina State University, Raleigh, NC, USA.
authors.forename: Siwen
authors.initials: S
authors.lastname: Liu
authors.affiliation: Industrial Design, College of Design, North Carolina State University, Raleigh, NC, USA.
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Wang
authors.affiliation: Ergonomics Division, Occupational & Environmental Safety, Duke University, Durham, NC, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dunn
authors.affiliation: Bosco Perry Design, LLC, Potomac, MD, USA.
authors.forename: Shane
authors.initials: S
authors.lastname: Cohen
mesh_terms: D000328:Adult; D001248:Asthenopia / Q000209:etiology; D001290:Attitude; D003246:Conservation of Energy Resources; D006804:Ergonomics; D005260:Female; D006801:Humans; D008029:Lighting / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000209:etiology; D011187:Posture; D017132:Workplace; D055815:Young Adult
keywords: Musculoskeletal; discomfort; posture; usability; vision