Modern physiology may help you to sleep better:

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Our globe circulates around the sun once a year since beginning of time. The globe also rotates around itself in a space of 24 hours i.e. one day and one night.At the equator the day is twelve hours and the night also twelve hours all year around. The further north or south you come the differences between days and nights become larger, so if you live very far to the north you might have no daylight in winter but in summer you can see  the midnight sun. This is a part of reality which can damage your sleep.

Modern times complicates these patterns of light. Many peoples nowadays spend a lot of time indoors and almost never go out.  The working population of Europe spend between 10 and 20 percent of their time in the open air and the American population even less; the average American spend 87 percent indoors and 5.5 percent in the car according to The National Human Activity Pattern Survey.  The last decades we have also gotten a lot of artificial lights from cellphones, computers, TV, e-books and LED lights and all those have a blue light which can disturb our ability to  sleep.

Our ancestors had from the beginning quite a different situation. At daytime they spent most of the time outdoors in order to get food and at night they rested and slept in their caves. This way of life continued for thousands of years and it was only when the electric light came that the situation started to change.  Man and animals adapted to their light conditions for thousands of years. We developed our inner clock and the circadian rhythm which fit well to human life until recently. The clock and the rhythm followed the outside light; but now there are so many things which disturb the those physiological processes which our body acquired. The good thing is that we all still have the biological clock and  the circadian rhythm which we can restore- at least some parts.

We have learnt more and more about melatonin and its importance for our sleep. It is also a strong antioxidant which can work against oxygen stress in our body cells and especially in the power stations in the cell ( the mitocondrias). This could help us fight diseases.

Daylight and night darkness regulate the circadian rhythm and the biological clock(s).  The infrared light is an important part the sunlight although we cannot see it. It has long wavelengths and contains lots of energy. The large amount of energy in infrared light allows  it to penetrate quite deep into our body.

I. You have to open your window, go to the balcony or go out to get in contact with this light. This is  important if you want to get a better sleep. When your body and your eyes meet the infrared light things start to happen and your body awakens. During night melatonin is produced in the pineal gland in your brain. When the infrared light hits your eyes and your retina nerve signals tell the pineal gland to stop producing melatonin. Instead the power stations, the mitocondries of your body cells start to produce it. As the infrared light can penetrate rather deep into your body( between one to eight millimeters) a lot of mitondries  now can produce the important melatonin. Going out in the fresh air outdoors will help you to restore your circadian rhythm.

II. Another important thing is to finish the day in a way which fits with your biological clock.  Avoid strong light during the evenings at least one or two hours before going to bed. It is the blue light which is the worst for the circadian rhythm. Blue light exist in most screens like laptops, TVs, cellphones, e-books etc. It is not very wise to watch those screens before going to sleep.  Better to read paper books and watch other things.

This is a part of how modern physiology can help you to a better sleep.