Effect of Luminous Environment on Visual Performance and Visual Comfort of Subjects in Selected Age Groups

摘要

The present study was an attempt to examine the impact of varying levels of illuminance, brightness contrast between selected test object and its background, and age of the subjects on their visual performance and visual comfort. Landolt's ring subtending a visual angle of 4'31" of an arc served as the test object; visual details of which matched with numerous kitchen tasks, based on the evaluation of a panel of judges. In a repeated measures experimental study, 39 female subjects of age ranging between 21 to 50 years performed the Landolt's ring test against three brightness contrasts under six selected illuminances, in a simulated kitchen created specially for the purpose. Apart from descriptive statistics, inferential statistics like repeated measures MANOVA were computed, along with non-parametric test like Friedman's test. Age of subjects appeared to have significant impact on their visual performance, the same being significant (P<0.01) between young and old, and middle and old age groups. A comparison of main effect of illuminance of 500 lx and 300 lx, and 500 lx and 166 lx revealed no significant difference in the subject's performance. However, the main effect of illuminance levels of 100 lx, 72 lx and 17 lx on visual performance of subject of all ages against three brightness contrasts were found significant (P<0.01) when compared with that of 500 lx. Brightness contrast also seemed to influence the subject's performance under varying illuminances. The paper, in addition, discusses about designing luminous environment for optimal visual performance and comfort, and implication of the study on future research, action programmes and policy issues.