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Power of light

Zonsopgang

Natural light is healthy

The seasons show us how much we need daylight. The lack of light makes us tired. In winter we received only a fraction of the amount of light that reaches us in the summer. We bring in the dark season usually by in artificially lit rooms. Therefore, the quality of artificial lighting is so important.

Light biologists, psychologists, doctors and lighting designers all studying for a while how artificial light affects people. Not only the photoreceptors in our eyes respond to light stimuli. There is also a pigment in our organ that responds to light in the blue spectrum: melanopsin - a protein in the retina of our eyes. Cells in our eyes with melanopsin - a group of dedicated, non-visual ganglion cells - let the brain know whether it is day or night outside.

Light wakes us up!

Our retina can see electromagnetic waves with a wavelength between 380 nm and 780 nm (nm = nanometers, one billionth of a meter). Between these wavelengths are found all the colors of the light spectrum. Wavelengths just below the visible spectrum belonging to the ultraviolet (UV). Above the visible spectrum is the infra-red light (IR) or thermal radiation.

The intensity of the light is measured in lux (the Latin name for light). Depending on the wavelength we receive in any quantity, our mood changes. When the summer sun shines with its full light spectrum, with almost 100,000 lux, our mood literally lighter. The gloomy 3500 lux during the winter months, tempers our spirit. The intensity of light is particularly small if we are in buildings with artificial lighting. Therefore, the quality of artificial lighting is very important.

The lamps producers endeavor to offer high quality products to market. However, very often the only criterion energy consumption and not the quality of the light itself.

How is the quality of the light?

When we are outside on a sunny day, our body receives white light, infrared and ultraviolet. The light from a light emitting element appears white to our eyes when all the colors of the light spectrum are balanced. The release of melatonin - the sleep hormone - in the body is regulated by blue light. This was naturally a clever trick. Humans evolved with daylight. When our ancestors spent most of the day under the blue sky (with hunting and gathering) body suppressed the release of melatonin during the day. During a day in the outside air is the melatonin level in the blood is low. The concentration of the sleep hormone in our blood begins to rise at dusk, so we get tired.

The effects of artificial lighting

Remember the lighting can be normally found in schools, libraries, offices or hospitals. The most common fluorescent lamps - or neon tubes or compact fluorescent lamps, known as "lamps". Even today clarity the only quality criterion when it comes to interior lighting. In recent years, added the issue of energy efficiency, which marked the end of the good old light bulb. However, the light bulb is closest to natural sunlight.

Sunlight reaches the Earth's surface in a balanced color spectrum. The maximum light is in the blue-green region with a wavelength of about 500 nm. Because the brightness of the sun, our eyes see this as a yellowish white.

Compared with the sunlight spectrum of fluorescent lamps has a much higher proportion of blue. And it is this blue part an enormous influence on our circadian rhythm, wake and sleep phases of our body. The blue part of the light in our environment is important in the middle of the day because it makes us awake and alert. Many of us work for screens that emit light with a relatively high proportion of blue (flat, tablet, iPad). Therefore, we need a blue light filter glasses while working at night (blue light protectors) Contribute so that our circadian rhythm is not disturbed.

Bright artificial lighting

We need a clearly structured rhythm with enough light in the morning and correspondingly dark in the evening, otherwise our sleep-sleep rhythm is disturbed. People who do not sleep well, feeling tired all the time and are easily nervous. On the other hand, a sufficiently bright light during the day is important in offices, schools and universities. It is now known that people who study optimal brightness are more concentrated, because a sufficient amount of light body, mind and mood activates.

Every cell in the body has its own circadian rhythm. One-tenth of our genes is active at different times of the day and the night. Therefore concepts for optimal lighting relevant, especially in hospitals and nursing homes, because body cells divide at specific times of day when the body regenerates. Patients and nursing home residents sleep better at night if there were particular bright light during the day. This does not mean that there should be an overdose of blue light! The high proportion of blue light is a problem with fluorescent lamps (discharge) and LED flat screens in particular. If that light at night is used, warns us, and as a result we do not sleep well.

Therefore interior and the works are planned with screens and monitors. Lighting in offices should emulate and compensate for natural daylight. In this case, the light automatically adapts to the user needs and light requirements. The so-called "Smart Lighting Technology" means the interior is self-regulating and provides perfect viewing conditions and user comfort. The light in the early morning hours have a higher proportion of blue and warmer daytime. Office workers can this "transition effect" increase by using glasses when long time working on the screen, or later in the day.

Sunlight is healthy

People feel comfortable in the natural lighting conditions of good weather: blue skies and sunshine - a mixture of a cold blue sky and a yellowish white, warm sun. Using similar lighting concepts impressed with offices changed considerably. The office is no longer a place where you're going reluctantly, but even invited to stay longer.

Sunlight provides the full spectrum of colors as shown by the rainbow. Unfortunately the sunlight received in recent years a bad reputation. Because stratospheric ozone depletion are our fears of "damage" and increased invisible UV radiation. But is this really justified? Again, this is a case of "the dose makes the poison." Everyone knows that long exposure to sunlight leads to redness of the skin. However, if sunbathing is carefully controlled - without sunscreen - increases well-being and health. The sun is responsible for the production of vitamin D in the body, regulating processes in the cell and stabilizes our skeleton. Vitamin D has a protective effect on our immune system. An optimal level of vitamin D in the blood is about 50 ng / ml (ng = nanogramm, one billionth of a gram). Sufficient time in the fresh air and the sun helps the body produce vitamin D.

But our way of life has led to the fact that 90% of the population vitamin D deficiency. During the summer, most people avoid direct sunlight for fear of the "dangerous sun." Alfresco is protected immediately by the skin sunscreen. Yet it is precisely this sunlight to reach the skin to produce vitamin D in the body, regardless of skin type.

It is important to know that the wavelengths of the UV portion of the sunlight are composed of the so-called UV-A radiation (380-315 nm) and UV-B radiation (315-280 nm). Relevant for the production of vitamin D is how much UV-B picks up the skin. The absorption of UV-B is only of the summer sun between 11.00 hours and 15.00 hours. When the sun is lower, the UV-B is absorbed by the atmosphere.

If the skin is exposed to sunlight without sunscreen, take the vitamin D levels in the blood. To reduce the risk of sunburn and skin cancer, overexposure to direct sunlight should be avoided. However, 10 to 15 minutes are sufficient to produce vitamin D to 20,000 units. Of course it is possible to supplement vitamin D in pill form. But those who want to naturally regulate their vitamin D levels should always prefer daylight.

It seems too just to know whether there are factors that are good or bad for us. This article shows that light is not always light - meaning that light has a quality, and the higher the quality, the more comfortable it is for our highly sensitive sensing organs, eyes and skin.

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