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 (CFL) 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 Hollwich 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.
Grand Old Man
Prof. Fritz Hollwich (*1909, †1991) was a German ophthalmologist, professor of ophthalmology and a director of ophthalmological clinic. He worked in Munich, Jena and Münster. In his inaugural dissertation form 1948 he distinguishes a visual and energetic path of the sight apparats. Three quarters of total light are considered to have the energetic function and only one quarter to have a visual function. The energetic function is demonstrated by observing the levels of hormones and other substances in the body. Blind patients who regained sight after cataract operation helped him to demonstrate how vitality is enhanced and substances are returning to their natural levels when light can strike retina again. Prof. Hollwich observed stress hormone levels decrease in his patients after he had daylight fluorescent tubes installed in his waiting room. In this way he contributed to a better light in hospitals. He is an author of many medical methods, more than two hundreds specialized publications and of many books. There are ten or more editions of his Textbook of Ophthalmology, which is even after sixty years still considered to be one of the cornerstones of modern ophthalmology. Prof. Hollwich cofounded International Ophthalmological Academy. In his works, he also refers to John Ott, a pioneer of better artificial light. From the work of prof. Hollwich one can feel truthfulness, scientifical verity, German precision and courage to present things the way they are.
Dr. John Ott (*1909, †2000) was an American camera man and self-learned scientist. While working on the time lapse pictures for Walt Disney's Secrets of life series he found that some of the plants do not blossom and finally fade under warm fluorescent light. Step by step he discovered that artificial light that lacks some colour can have adverse effect on plants and animals. Large importance is given to the blue light, which is weak in warm white light. Ultraviolet light, which normally does not pass window or spectacles glass is also considered important. Dr. Ott demonstrated that a light more similar to daylight can soothe school kids, but also prison inmates. In this way he demonstrated how different kinds of light affect our hormonal system that, in the end, controls our body and our feelings. Dr. Ott was the first to talk about mallillumination. He is a founder of Time Lapse Research foundation, Bio Ecological Research Institute and Ott Lite company, which is one of the first producers of fluorescent tubes with rare-earth elements that enrich the spectrum of the light produced, enhancing the colour experience. Dr. Ott published several books, several tens of articles, made several thousands of lectures. In 1957, he was awarded a title of honorary doctor of natural sciences by Loyola University of Chicago. John Ott is an example of great enthusiast, unlimited by school indoctrinations, a pioneer of better illumination who gained respect of both laic and scientific public.
Dr. Norman E. Rosenthal (*1950) is a Southafrican psychiatrist living in USA. In 1984 he published an article on seasonal affective disorder (SAD) and it's healing by phototherapy. Dr. Rosenthal is an author or coauthor of more than two hundred specialized articles. He published four books: Winter Blues, The Emotional Revolution, St. John's Wort and How to Beat Jet Lag.
Dr. Jacob Liberman (*1947) is an American ophthalmologist and author of Light - medicine of the future and Take Off Your Glasses and See. He is an inventor of the EYEPORT eye training device and system.