Experts recommend that people obtain a minimum of seven hours of sleep every night and adhere to a consistent bedtime routine. However, When a person starts to creep into midlife, the average amount that people sleep at night decreases by 30 minutes every decade. Additionally, they tend to retire to bed earlier and rise earlier.
The numerous reasons why this led to happen.
The brain is the main culprit
The gradual shift towards earlier bedtimes and waking up is primarily attributed to changes in the brain. As we age, the brain, like other bodily systems, becomes less responsive.
According to HuffPost, the director of the Center for Sleep and Circadian Sciences at the University of Arizona Health Sciences, explained: "The wiring of the brain is likely not sensing ... and responding to the inputs as well as it should because it’s an aging brain."
Daylight, social cues, mealtimes, and physical activity act as markers that help us establish where we are in a day.
If confined to a dark room without any external stimuli such as light or food, apart from being a form of torture, it would also prove exceedingly challenging to determine what day and time it is.
In the case of teenagers, their brains are attuned to receive and interpret these cues. Conversely, natural brain degeneration in older adults disrupts the links in the brain.
Consequently, older individuals tend to feel fatigued earlier in the day compared to younger generations, leading to going to bed earlier, so they wake up earlier too.
Eyes are a reason why you sleep earlier
The eyes also play an important role in receiving external signals, and, of course, vision changes with age.
Professor Cindy Lustig a member of the cognition and aging laboratory at the University of Michigan, explained: “Interestingly, one of [the reasons] seems to be that the vision changes that come with age reduce the intensity of the degree of light stimulation that our brain receives, which plays an important role in ‘setting’ our circadian clock and keeping it on track,”
According to Parthasarathy, they said: “If there are cataracts, the evening light doesn’t go into the eyes as much, so, according to the brain, sunset is earlier than when it actually set."
The impact is reflected in the body's melatonin levels, which are often referred to as the sleep hormone and typically begin to rise after sunset.
Your brain was deceived by cataracts, causing it to perceive an earlier sunset than reality. So, it can cause melatonin levels to rise prematurely and make you go to bed earlier
However, the tendency to go to bed earlier and wake up earlier is a natural part of aging.
