Final answer:
If people are not exposed to natural light and dark cycles, they may experience a range of issues due to circadian rhythm disruption, including difficulty sleeping, staying awake, and maintaining a consistent sleep schedule.
Step-by-step explanation:
When people are not aware of the cues that signal day or night, such as during long-haul flights or when working night shifts, several issues related to circadian rhythm disruption can occur. These issues are not just limited to one symptom but can encompass a range of difficulties that include: trouble sleeping, difficulty staying awake during the day, and challenges in maintaining a regular sleep schedule. Essentially, the lack of exposure to natural light and dark cycles can lead to a mismatch between a person's internal biological clock and the external environment, leading to symptoms of jet lag, sleepiness during the day, insomnia, and decreased alertness.
Our body's sleep-wake cycle, or circadian rhythm, is regulated by the brain and aligned with the external environment's cues, notably daylight. Light exposure is integral for setting our biological clock, and disruptions in this cycle can lead to a variety of negative outcomes. In order to realign our biological clocks with the external environment, strategies like bright light therapy during waking hours and ensuring darkness during sleep hours can be used to mitigate issues such as insomnia and mood disturbances.