LIGHT AND HEALTH
Tailored morning light
to improve sleep, fatigue, and everyday living in Parkinson’s disease — A follow-up study By MARIANA G. FIGUEIRO, PHD Light and Health Research Center at Mount Sinai
Figure 1. Light’s effects on the circadian system by day (left) and by night (right).
Sleep disturbances are among the most common nonmotor symptoms in Parkinson’s disease (PD), affecting up to 90% of individuals living with the illness. These difficulties—ranging from trouble falling asleep and frequent awakenings to restless legs and vivid dreams—often coexist with fatigue, a pervasive physical or mental exhaustion that is not relieved by rest. Importantly, fatigue and sleepiness are not the same 22
designing lighting
thing. Many people with PD report profound fatigue even when they do not feel sleepy, and the consequences for everyday living and overall health can be substantial. At the center of these challenges is the body’s internal clock— the circadian system—which coordinates timing of sleep and waking alongside daily rhythms in hormone release, body