The Effect of Lighting on Performance of Tasks Requiring Near Vision in Older Adults

PURPOSE: With age, more light is needed in order to function (Perlmutter, 2012), but the effect of lighting on occupational performance has received little attention in occupational therapy. The purpose of the study was to determine if lighting affects older adults’ ability to perform selected occupational tasks that require near vision and if lighting levels affects their perceived effort while performing selected occupational tasks. The research questions were, What is the impact of lighting on older adults’ performance on selected tasks that are visually challenging, and what is the impact of lighting on perceived effort of older adults while performing tasks that are visually challenging?

DESIGN: A quasi-experimental, repeated-measures design was used with a convenience sample recruited from a retirement community. Thirty participants met the inclusion criteria, which included visual and cognitive screening. The mean age of the 30 participants was 83 yr, and most (80%) were female.

METHOD: Participants completed three occupational tasks (reading a prescription label, sorting pills, and sorting dark-colored socks) under three different lighting levels (low, M = 103, medium, M = 127, and high, M = 397 foot-candles) presented in random order. Participants were placed in three groups based on order of lighting presentation and completed each set of tasks four times, a trial session followed by three timed sessions. Participants were asked to rate their perceived effort under each lighting level using the Rating Scale Mental Effort (Zijlstra, 1993). Descriptive statistics were used to examine completion times, groups, and lighting levels.

RESULTS: Two tasks required the most time to complete under medium lighting: reading a prescription label (M = 11.80) and sorting pills (M = 66.48). Sorting socks required the highest mean time under the low lighting level (M = 23.33). The lighting level under which tasks were performed the quickest varied for each task: reading a prescription label (low lighting, M = 9.52), sorting pills (high lighting, M = 39.62), and sorting socks (medium lighting, M = 19.71). Group 1 participants were the oldest (M = 84.6 yr), had the poorest vision, and generally required the most time to complete the tasks. Participants rated the most effort under medium lighting (M = 15.31) and the least effort under high lighting (M = 12.95).

CONCLUSION: A goal of the study was to determine if there was a difference in task performance based on lighting level. The results suggest lighting may have affected performance and perceived effort of older adults while completing the visually challenging tasks. There was not a specific lighting level under which tasks were completed the most quickly, but in general tasks required the most time to complete under the medium lighting level. Another goal was to investigate the effect of lighting on older adults’ perceived effort when performing visually challenging tasks. The greatest amount of effort was reported under the medium lighting level, and the least was reported under the high lighting level.

IMPACT STATEMENT: There is a need for occupational therapy practitioners to better understand the challenges of older adults during occupational performance, including the impact of lighting on tasks requiring near vision. There is also a need to better understand the perceived effort of older adults during occupational task performance.

References

Perlmutter, M. (2012). Home lighting assessment and modifications. Visibility, 6(1), 6–9.

Zijlstra, F. (1993). Efficiency in work behavior: A design approach for modern tools. Doctoral dissertation, Delft University of Technology, Delft, The Netherlands.