Exposure of the eyes to light of sufficient intensity and duration at the appropriate time of day can have profound effects on the quality, duration, and timing of sleep. Environmental light plays a fundamental role in regulating circadian physiology. Melanopsin in the ganglion cells absorbs light energy and triggers phototransduction resulting in physiological responses in the suprachiasmatic nucleus (SCN) via the retinohypothalamic tract. Aging is also associated with decreased exposure to light and decreased transmission of light to the retina due to changes in the anterior chamber of the eyes. Light therapy appears to have a good safety record. There are no compelling data available pertaining specifically to the duration and treatment of light therapy for older adults. Supporting strength and stability of other zeitgebers, including activities, exercise, meals, and coffee and tea breaks, may have an additive effect with the improvement in natural light exposure.