[Purpose] The purpose of this study was to examine the effects of changes in indoor brightness on sway of the body during static standing and immediately after standing up. [Subjects] The subjects were 10 healthy young adults and 10 healthy seniors. [Methods] We set indoor illuminance at 1000, 100, 10 and 0 lux. We measured swaying of the body during static standing and immediately after standing up in the young and elderly subjects, and compared the body sway of the young group with that of the elderly group. [Results] This study indicated that circumference area under during static standing increased as the illuminance decreases in both young and elderly groups, but there was not significant illuminance-groups interaction. In both groups, there were no significant differences in total trajectory length and circumference area during static standing and immediately after standing up among illuminance. In the elderly subjects, total trajectory length and circumference area immediately after standing up were significantly higher than in younger subjects at each illuminance. [Conclusion] This study suggested that postural control during close legs static standing in the elderly group was not so dependent on visual sense.
