Bright Light Therapy’s Effect on Night Shift Health Care Workers Who Suffer from Light Induced Misalignment of Circadian Rhythms

Abstract

Modern-day society is based on a high pace lifestyle that people are constantly attempting to keep up with. The invention of the light completely changed society, allowing people to work outside of daylight hours. As countries become more and more industrialized, the need for 24/7 productivity becomes more and more common. From transportation to mining to medicine, individuals willing to work unconventional hours are necessary for the sustainability of the industry. This group of people, working outside “normal” work hours such as between 7 a.m. and 6 p.m. or shifts longer than eight hours, are known as shift workers. They make up about 26.5 million people in the employed population in the United States and about 100 million around the world (Moore-Ede & Platika, 2018). Shift work affects a person’s circadian rhythm, causing issues. “Circadian rhythm mainly controls the daily wake and sleep cycle and regulates physiological processes including hormone secretion, body temperature, feeding behavior, cell cycle progression, and drug, glucose, and xenobiotic metabolism” (Khan et al., 2018, p.2). This circadian rhythm is controlled by the circadian clock and is regulated through clock genes. Light exposure greatly influences circadian rhythms and specifically affects the release of the hormone melatonin which activates specific receptors MTI and MT2 that mediate sleep-promoting effects.