This pilot trial studies how well systemic light exposure works in preventing frailty in older patients with prostate cancer on hormonal therapy. Hormone therapy causes many symptoms of frailty in older men including fatigue, slower time to walk a specified distance, reduced activity levels, loss of lean muscle, and muscle weakness. It is not yet known if systemic light exposure may reduce frailty in older prostate cancer patients.

PRIMARY OBJECTIVES:

I. Determine if bright white light (BWL), compared to dim white light (DWL), significantly prevents frailty development in older prostate cancer (PC) patients following prostate anti-androgen therapy initiation.

II. Determine if BWL, compared to DWL, significantly increases functional performance and physical activity levels, yields significant reductions in fatigue, lowers body mass index (BMI), and reduces weakness in older PC patients following prostate anti-androgen therapy initiation.

EXPLORATORY OBJECTIVE:

I. Examine the feasibility of collecting and storing clinically-usable bio-measures for future analysis in patients at baseline and if available at 6 months, including blood samples (inflammatory markers), and salivary swabs (genetics, genomics, cortisol circadian rhythms).

OUTLINE: Patients are randomized to 1 of 2 arms.

ARM I (BWL): Patients wear an Actiwatch for 5 days at baseline, 3 months and 6 months. Beginning 1-4 weeks after first anti-androgen therapy, patients undergo BWL treatment using Luminette glasses for 30 minutes every morning for 3-6 months.

ARM II (DWL): Patients wear an Actiwatch for 5 days at baseline, 3 months and 6 months. Beginning 1-4 weeks after first anti-androgen therapy, patients undergo DWL treatment using Luminette glasses for 30 minutes every morning for 3-6 months.

Inclusion Criteria:

• Prostate cancer (PC) patients who are starting androgen deprivation therapy (ADT), abiraterone, or enzalutamide with plans to continue for at least six months with minimal evidence of disease burden in accordance with current standards of care.
• A life expectancy of 6 months or longer.
• All subjects must have the ability to understand and the willingness to sign a written or electronic informed consent.

Exclusion Criteria:

• Significant pre-existing frailty precluding completion of baseline assessments.
• Other active malignancies
• Previous use of radiation therapy within the year prior to consent.
• Widely metastatic disease.
• Confounding serious medical illnesses which causes frailty.
• Severe sleep disorders.
• Eye diseases which limit the ability of light to be processed.
• Severe psychological impairment.
• Current employment in night shift work.
• Previous use of light therapy to alleviate fatigue or depressive symptoms.
• Secondary cancer diagnosis within the past 5 years.
• Plans to travel across meridians during treatment.
• Uncontrolled illness including ongoing or active infection in disease status patients.