This study looks at how adults use an iPad-based light app in everyday life.
Light is the main signal that sets the body's internal clock, which controls daily rhythms in sleep, alertness, and many other body systems. Indoor living means many people do not get bright light at a consistent time each day.
The app uses the iPad screen to deliver light while people watch videos, read, or browse. It suggests about one hour of use per day, started within about two hours of waking. It does not require anyone to follow that schedule, and no one is locked out for using it more, less, or at other times. The app shows people when they are positioned to receive the intended light, records how the app is used, and asks short questions about sleep.
The main questions this study aims to answer are:
Participants will use the app on an iPad for up to eight weeks, answer short questions about their sleep and how they feel, and share feedback about their experience.
Participants may also choose to take part in optional sub-studies. They can wear a device the sponsor provides to record movement, light exposure, and skin temperature, or share data from a wearable device they already use. They can also give blood, saliva, or urine samples, which researchers will use to describe daily patterns in clock-related genes and other markers. These sub-studies are entirely exploratory and voluntary, and participants can take part in the main study without them.
Participants will not receive results from any samples they give. This study does not provide medical treatment, and it is not designed to determine whether the app treats or improves any medical condition.
Inclusion Criteria:
Exclusion Criteria:
Participants receive the investigational Circadian OS iPad-based light app and use it in their normal environment over a defined exposure period. App onboarding presents a recommended use envelope of approximately 60 minutes per day within approximately 2 hours of habitual wake time, anchored to the participant's Munich ChronoType Questionnaire response. Use is not enforced: the app does not lock out participants who use it less, more, or outside the recommended window, and non-use is recorded as participation data. Participants complete brief in-app check-ins on sleep and experience, plus periodic usability surveys. Optional sub-studies (actigraphy, biomarker collection, moderated human-factors observation) are independently elected by participants within this single arm.
New York, New York 10001, United States
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