Light and Health

Since the very beginning of mankind's existence on Earth, we have been used to sunlight during the daytime and darkness at night. Just a hundred and twenty years ago people spent most of the day working in sunlight and went to bed after dark. Nowadays, most of us live the "modern" western lifestyle - we work in artificially illuminated rooms, turning our lights on after dark in order to stay up longer.

At first, to get light, people used fire, torches or candles. Later on they used oil lamps and then came kerosene and town gas. Finally, people got used to the light of the first electric bulbs, despite the fact they found themselves looking ugly in the beginning. After a number of improvements we grew accustomed to using fluorescent tubes, although, initially, their quality was more suitable for scenes from horror movies. These days we are witnessing an incandescent dusk, as compact fluorescent lamps (CLF) take over. Many people complain about CFL light so the quality of light is often a current topic of discussed.

In the 1980's Professor Holwich found that high stress hormone levels in his patients fell after he replaced the cool-white tubes in his waiting room for daylight tubes. Thanks to him, the use of cool-white tubes with poor colour rendering was later forbidden in German healthcare establishments.

Today, it is possible to manufacture fluorescent tubes which produce light that is 98% equivalent to sunlight. However the market is dominated by tubes that produce light that is merely 80 % similar to sunlight - which is also the minimum level stipulated for workplace lighting. Commercial CFLs suffer even poorer colour rendering as the market is driven by price rather than quality.

As CFLs are going to replace incandescent bulbs, a rising number of complaints can be expected from dissatisfied customers. It is necessary to inform customers about the differences in the quality of light sources available and the impact of using one or another, and to offer them better light sources if they are not satisfied with those commonly sold. We perceive about 80% of information by sight, and visual comfort thus contributes greatly to the overall quality of a person's life.

Most CFLs found on the market emit a yellowish-white light. Their advantage is that they resemble a light bulb and that interiors with lower light intensities look cosier in warmer light.

Research carried out in Holland clearly shows that people need high levels of illumination and a chromatic temperature of about 6500K to stay alert and productive, avoid errors and accidents and stay fresh long. Very bright white light is also used in medicine to combat depressions.

Is cold light better than warm light? The best light is sunlight, whose intensity and tone changes during the day - from warmer in the morning, through colder at midday and again warmer in the evening. Biodynamic lighting systems track these changes so that we can feel more like we are outdoors when we stay indoors. Such systems can be set in various ways. They can automatically follow outside light conditions or use timed programs. Alternatively they can be manually controlled according to the user's needs or mood.

Experience always shows us that every imitation has its drawbacks compared to the natural or original state of things. We are witnessing alternating waves. One being the enthusiasm of science and technology, which is constantly aiming to provide us with new possibilities and more comfort. The other being a return to nature, which provides us with everything in the original, familiar and often laborious form. How we connect these two seemingly opposite ideals is up to us. Examples of technology inspired by nature include organic foods and supplements, organic cosmetics, environmentally friendly detergents, water filters, fibre optics or high quality and healthy lighting.

Healthy light brings visible quality to one's life.