Effects of computer monitor viewing angle and related factors on strain, performance, and preference outcomes

A model of visual and musculoskeletal strain associated with computer monit or placement was developed. The main premise of which is that monitor place ment decisions must take into consideration development of both visual and musculoskeletal strains. Certain factors in the model that were thought to affect one or both types of strain, or that were considered important to ru le out for effect, were tested in a lab setting. These factors were viewing angle (eye level, midlevel, low level), monitor size (14 in., 19 in.), key board familiarity (touch typist, nontouch typist), and task (reading, mousi ng, typing). Outcomes included indicators of visual and musculoskeletal str ain, preference, and performance. Muscle activity was generally greater for the low viewing angle, for the standard monitor (14 in.), and for non-touc h typists. Participants preferred the midlevel placement. Task performance was slightly diminished with eye-level placement. Results are interpreted i n relation to the model and to several hypotheses that were formed to focus the inquiry. Actual or potential applications of this research include mon itor placement decisions in the design or modification of computer workstat ions.