Project Summary The NIH has recognized the importance of circadian rhythms and sleep in Alzheimer’s disease (AD) and related dementias (ADRD) progression, recently releasing a Notice of Special Interest titled “Sleep Disorders and Circadian Clock Disruption in Alzheimer’s Disease and other Dementias of Aging.” The NIH has also noted that improving sleep quality is among the few interventions that people can take to reduce the risk of developing AD/ADRD later in life. Light therapy has shown great promise as a non-pharmacological treatment in helping to regulate sleep and in improving cognition in older adults with AD/ADRD. Perhaps not surprisingly given our evolutionary history, studies in this area can be simply summarized as: bright days and dark nights are beneficial for human health generally and AD/ADRD health specifically. Studies have demonstrated that daytime light exposure can consolidate and increase nighttime sleep efficiency, while also increasing daytime wakefulness and reducing evening agitation in AD/ADRD patients. But critical knowledge gaps exist, including information on the light exposure humans typically experience—at both individual and population levels—and how these vary from optimal light exposure patterns. Also missing are tools to collect these data and tools for individuals, researchers, and caregivers to monitor and control light exposure. In order to address these gaps, researchers have developed a novel, cost-effective, battery-powered light spectrometer which can measure circadian light characteristics and be discreetly mounted to walls or used as a wearable. This networked device provides continuous, remote data collection and storage, allowing interested parties to easily monitor circadian lighting conditions and adjust their lighting as needed. This project would build on these researcher-oriented tools and technologies to commercialize a new consumer- oriented version of this light exposure tracking system targeting patients with mild cognitive impairment (MCI) or early stage Alzheimer’s disease still living at home. Light exposure data collected by these systems would be used to provide actional recommendations and/or automations to improve circadian entrainment and overall health of AD/ADRD patients. The work proposed here will focus on the development of a new light exposure tracker, companion apps, and dashboards that gather much of the same detailed lighting data as the researcher- oriented device, but present these data in ways that are understandable and helpful for people with AD/ADRD and their caregivers. Integrations with related connected products, such as sleep trackers and smart lamps, will also be investigated. A clinical trial is proposed that includes both MCI and AD/ADRD patients living at home. The trial will characterize the light exposure that these cohorts experience and test a variety of interventions intended to bring their light exposure patterns more in line with patterns known to suppor...