The goal of this randomized, cross-over, single-site trial followed by an exploratory third intervention is to understand how indoor lighting affects different measures of brain health in older adults living in independent living residences. This is a community based study occurring in a local senior living facility. The main question this study aims to answer is:

- How does the quality of ambient indoor lighting an older adult is exposed to affect measures of brain health, such as sleep quality, physical activity, cognitive function, and social engagement?

Participants will be exposed to three different indoor lighting conditions for 4 weeks each while performing the following tasks:

• Wear a smartwatch throughout the study to measure sleep quality and physical activity
• Wear a small, wearable light sensor to measure light exposure during waking hours
• Perform cognitive assessments throughout the study to detect any changes between each of the lighting conditions
• Complete self-report of surveys to assess independence, social engagement, sleep quality, and mood

Results from these tasks will be compared within and between subjects to assess whether the different lighting conditions affect these different measures of brain health.

Inclusion Criteria:

1. At least age 60;
2. Able to wear wearable devices throughout the study;
3. Willing to have their lighting in their kitchen and dining areas changed and controlled for the study;
4. Willing to have environmental sensors placed in their residence;
5. Willing to provide contact information about their primary care provider (PCP); and
6. Able and has capacity to provide informed consent (score > 14.5 based on UBACC consent capacity form).

Exclusion Criteria:

1. Is legally blind
2. Previously renovated their living units and no longer have the standard lighting installation offered by the Senior Living Facility;
3. Currently spend or plan to spend most of their day outside of their residence during the study (i.e., would not experience the indoor lighting intervention for the majority of the study);
4. Plan to travel to a different time zone during the study; or
5. Plan to be away from their residence for more than a week during the study.