The impact of LED lighting on people's work performance between different age groups

An experiment was carried out to study the work performance for the children, youth and aged groups including 12, 17 and 18 subjects respectively. Note that there have been very few studies to compare lighting impact on different age groups. For the children group, 5 sources had 3 CCTs (3000, 4000, 5000K), each having Circadian Stimulus (CS) values of 0.22 and 0.42. For the youth group, only 3 sources having the same 4000K as the young group were studied. Their CS values were 0.26, 0.41 and 0.44, respectively. For the aged group, there were 4 sources including 3000 K, 4000 K and 6500 K with CS about 0.4 and the other 4000K with CS at 0.26. About 10 tests were employed including questionnaire (KSS, mood, PANAS, fatigue), performance (d2, reading, Schulte grid) and eye fatigue (CFF and Landolt ring). It was found that the results from all three groups showed a high CS source to have a higher work performance. For the youth group, 4000 K found to give a highest work performance. For the aged group, a higher CCT showed a better performance. The results also showed a general trend, i.e. eye fatigue and work performance have a negative correlation.