Sleep is mandatory for good health. There is a healthy range of around seven to nine hours for adults. When you are outside that range – above or below – your long-term health can be impacted

Power of Sleep and Health,the%20brain%20cannot%20function%20properly. Our bodies (and minds) require sleep to recharge and repair. We have an internal body clock called the circadian rhythm. It regulates our sleep cycle.

Light affects our circadian rhythm. The hypothalamus in our brain has special receptors (suprachiasmatic nuclei) that process light – natural or artificial. It helps our brain determine whether it is day or night. As the light gets dimmer as night approaches, our bodies make melatonin, increasing our need for sleep. The reverse happens in the morning when cortisol is produced to promote alertness and energy.

How Much Light Affects Us at Night? A recent small study of twenty healthy adults ( found that one night of sleeping with the lights on created measurable health events compared to one night of sleep with the lights off.

Those sleeping with the lights on had higher pulse rates during their sleep and awoke with higher insulin levels. The study results pointed out that this small study may indicate a problem that could develop over time – years. How little light affects us during sleep is debatable.

The Moon and Sleep,hormone%20cortisol%20during%20full%20moons. Thousands of years of human existence has seen the moon bright and non-existent. Has the moon’s brightness for those sleeping outdoors been a factor in long-term health? I do not think anyone knows since we cannot measure, test, and evaluate our ancestors.

However, we do know that moonlight is the reflection of sunlight that affects the creation of melatonin. Studies have tested and measured melatonin levels with the cycle of the moon. In men patients, both melatonin and testosterone were lower during the full moon phases. Additionally, cortisol levels were also higher.

These studies were done in Sweden with over 800 people. However, the measurements were for one night of sleep. Men and women were affected differently. The difference was less than a half-hour in the total sleep each night, and the men were more sensitive to the phase of the moon.

Red Light at Night We see a red light in military command centers, onboard ships, cockpits of aircraft, astronomy labs, and more. It is to improve your night vision. However, does it affect your sleep?

There have been numerous studies on red light and sleep. A crucial factor in determining the red light is the frequency of the light. Many red lights are tinted red and are not representative of true red light.

A study was done in 2012 of Chinese basketball players ( using red light therapy to evaluate the performance of athletes. Red light therapy stimulates the mitochondria to produce more energy and endurance.

The results were improved sleep, increased melatonin levels, and better endurance than the placebo group with no red light therapy.

A more recent study (just before the pandemic) tested an office environment by combining red and ambient white light. Again, a measurable difference was noted post-lunch in alertness and energy levels than measurements before the test.

Sleep inertia is a measurable state of cognitive impairment and sensory-motor performance immediately after arising from sleep. It is the transition from sleep to being fully awake. Does red light impair sleep inertia?

Measurements were taken in one to three-minute intervals after awakening showed that red light does not suppress melatonin, and results do not affect sleep quality.

Light to Avoid Before Sleep

Blue light is common in many computer screens, cell phones, and other electronic devices. I had headaches and eye strain when I bought my current monitor a couple of years ago. I could go five or ten minutes and begin to feel eye strain, and another ten or fifteen minutes resulted in the beginning of a headache.

I bought a cheap pair of blue light glasses, and I work with the monitor for hours a day without any eye strain or headaches. Blue light helps our bodies adapt to the day. It makes us feel more alert. However, at night it is harder to fall asleep and stay asleep.

Avoid fluorescent lighting, LED lights, televisions, cell phones, tablets, computer screens, gaming devices, and the like for a couple of hours before bed. If you have sleep problems, this might be an easy thing to address.


Quality sleep is needed for long-term health. So a night or two (and probably even a few more) will not be a big deal. Yes, you will feel groggy for a while, but a good night’s sleep will correct it.

The incremental impairments from having a light on in your bedroom while sleeping still need to be evaluated over months, if not years. Leaving a television on while you sleep might be one of the most detrimental to long-term health. Both the blue light and the background noise affect sleep quality and your circadian rhythm.

Sleep is one factor for long-term health. Exercise, diet, stress management, weight management, and more lead to a longer and healthier life. Many factors play in sleep patterns. Being aware of those that can affect you and making changes to improve sleep might be one of the wisest things you can do today and in the months to come.

Live Longer & Enjoy Life! – Red O’Laughlin –

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