The application, influence, and potential benefits of using various lighting techniques to aid healthcare, wellness, and recuperation in holistic medical applications
The application of light and lighting techniques to healthcare and wellness is a wide ranging topic, and there is a myriad of related information on the subject. Much research and learning has taken place over many years dating from ancient times where the Greeks Romans and Egyptians used the healing properties of sunlight to Danish Professor Niels Ryberg Finsen in the early 1900’s to the present day.
Much of the information available, particularly on ‘alternative’ lighting applications has not necessarily been proven and much is subjective, but in many cases positive results appear to be achieved.
At the base of all of this is the function of the eye and brain with respect to light, and human psychology and visual perception. In the nature of subjectivity, every persons reaction to light is different and many ‘treatments’ are about belief that it will work for the individual person on some level.
The purpose of this paper is to look at, and review, the various aspects of light and its positive effects in promoting human health.
There is an increasing interest in alternative and holistic medicine, but when it comes specifically to the use of light, general knowledge in the subject appears to be limited to what we learned in university about simple treatments for Seasonal Affected Disorder (SAD) etc. Here we take a brief look at the history of this subject, review some of the facts and information are out there in terms of these lighting techniques and to try and draw some conclusions.
The Sun and therefore light provided the basis for the development of all life on our planet. References for a therapeutic use of light can be found in many cultures through history.
In ancient Egypt man worshipped the Sun. In the ancient city of Hepliopolis the sun god was worshiped in many guises and there were gods for rising sun, mid-day sun, and setting sun. The temple of Heliopolis had a quartz crystal in the dome that split sunlight into the seven prismatic colours of the spectrum. These coloured rays of light filled seven healing chambers where people received ‘colour healing’.
The ancient Greeks attached great importance to what they called heliotherapy or solar therapy. Later the Romans refined this with their bathing culture and had houses built with the first natural solariums.
We know from our own individual experiences that not only plants growth depends on light, but humans are biologically dependent on it too. From a simple psychological point of view if the sun shines we are in a better mood and more active. And we know we require exposure to the sun to activate the development of vitamin D in our bodies. Natural daylight and sunlight is critical to our wellbeing in so many ways so how can both natural and artificial light be used for medical applications?
Medical applications of light therapy
Modern science has researched the ‘biological effects of light’ for more than 100 years and a number of applications have been developed for light therapy. These include:
Dermatology Physiotherapy Sports Medicine Rheumatology
Psychiatry Rehabilitation Surgery Parkinson’s disease
Light enters the body through both the eyes and the skin. If a person is blind it is believed that the body compensates by taking more light through the skin. As well as light entering the eyes allowing us to see, light is also transmitted through the nervous system from the retina to the hypothalamus, a very sensitive part of the brain which affect many parts of our body.
The first evolution of a phototherapy system that could emit light similar to sunlight was developed in 1896 by Danish Professor Niels Ryberg Finsen. With this system Professor Finsen won the Nobel prize in 1903 for his successful treatment of a certain type of skin tuberculosis. The device used generated technically synthesized sunlight.
Sunlight is long known to improve acne vulgaris. This was thought to be because of the anti-bacterial effects of the ultra-violet part of the spectrum.
Visible violet light, present in sunlight, in the range 405 – 420 nm ultimately kills the bacteria and the application of this UV light for three consecutive days potentially reduces the bacteria in the pores by 99.9 per cent. However, long term use of UV treatment is generally restricted due to the potential for permanent skin damage.
Psoriasis and Eczema:
A feature of psoriasis is inflammation mediated by the immune system. UV radiation is known to suppress the immune system and reduce inflammatory responses. Light therapy uses UVA ( 315 – 400nm ) or UVB ( 280-315nm ). U.V. light is exposed to the affected area of skin to activate part of the body’s immune system. The light kills so called ‘T’ cells which slows the process of inflammation and causes the loss of skin cells to slow down.
Wound and post-operative scar healing:
Monochromatic infrared light at a wavelength of 890nm is used to help restore sensation and reduce pain. This effect was previously noted by surgeons in the first world war, who used sunlight to reduce pain and aid healing.
Mood and sleep-related applications:
The part of the brain called the hypothalamus has control over the pineal gland which is responsible for the production of melatonin. We need melatonin for sleeping at night and conversely we need serotonin to be active during the day. This process is called the circadian rhythm and therefore our normal body function with regard to required waking and sleeping pattern is light dependent.
Seasonal Affected Disorder (SAD) is related to an imbalance in the body’s natural circadian rhythms. In the 1980’s it was discovered by scientists that exposure to bright white light is very effective at treating SAD. While full sunlight is the optimum solution for SAD, light boxes with fluorescent lamps can also be effective.
For the purpose of manipulating melatonin and serotonin levels light boxes providing intense illumination are effective. They typically provide 2500 lux to 10,000 lux without UV to the eye. Exposure durations can range from two hours for 2500lux to thirty minutes for 10,000 lux. For S.A.D. the timing of the exposure is relatively unimportant. Many manufacturers of these light boxes promote the use of ‘full spectrum’ light with fluorescent lamps, but respected research indicates that this is not necessary and that simple white light at the correct lux level to the eye is sufficient.
Recent research also suggests that deep blue light can also be effective until old age when the yellowing of the eye blocks blue light.
Circadian rhythm sleep disorders:
Shift working or crossing several time zones significantly affects circadian rhythm (jet lag). When the circadian period is phase shifted (lengthened or shortened causing such affects) this leads to significant changes in mood and concentration.
As with SAD the judicious use of ‘light therapy’ whether artificial light or natural daylight / sunlight can help rebalance circadian rhythm and speed recovery from jet lag. Unlike treatment for SAD the timing of the light therapy exposure is important to re-set the body clock. NASA have even used this type of therapy to prepare astronauts for night-time launches.
Research has shown the efficacy of light therapy to assist the liver in lowering the levels of bilirubin which accumulate in the liver of newly born babies, leading to jaundice and potentially mental retardation or even death. The common treatment for this condition is blue visible light.
Dr. Duncan Anderson of Hammersmith Hospital in London has been working for many years to use Photic Stimulation (pulsed light) to treat migraine headaches. The light treatment involves a pulsed light in front of each eye and it was found that with a study of fifty patients, attacks were shortened in all cases and the frequency of attacks was also reduced.
Muscle and bone atrophy are well documented in astronauts, and various minor injuries occurring in space have been found not to heal until landing on earth.
Studies by NASA have shown that human cells need gravity to stimulate growth. As gravitational forces increase or decrease, the cell function responds in a linear fashion. This poses significant health risks for astronauts on long term space travel. A form of light therapy with LEDs has been developed by NASA to stimulate the basic energy processes in human cells, particularly when ‘near infra-red’ light is used. The optimal wavelengths were found to be 680, 730, 880nm and it was also found that this system could also improve wound healing.
It has been documented that light therapy can be used to reduce patients' tremors.
The use of light and colour in health spas
Colour psychology is the study of the effect that colours have on human behaviour, instinctive feelings and physical responses.
In modern ‘health spas’ today, light and colour are often used therapeutically for the well-being of ‘mind, body and soul’. They are often used in combination with other sensory elements of sound and smell in meditation rooms and therapy treatment rooms. There is less scientific evidence for such benefits although general research has been carried out and the positive effects of using colour and light can be seen and felt.
As the Ancient Egyptians used colour light treatments in the temple of Heliopolis, so today’s health spas use light and colour to create various positive psychological responses. Each of us reacts differently to colours but there are some basic characteristics for each colour which elicit typical human responses.
Many ancient Sanskrit writings describe the body as having seven major energy centres known as chakras. These chakras are located at the sites of the major endocrine glands and correspond to particular states of consciousness and personality types. Each is responsive to a different colour.
More recent research such as by Robert Gerard in 1958, Dr. Harry Wohlfarth, also 1958, showed how humans responded to different colours. Particularly it was shown that, in simple terms red and orange light can raise blood pressure and pulse rate, while blue and green light can lower blood pressure and pulse rate. Other researchers ( B.S. Aaronson, 1971, and Plack and Schick, 1974 ) also found that mood was affected by different colours.
However, the Sanskrit / colour relationships used in health spa treatments go much further than this:
Violet / Purple relates to the crown chakra which is at the top of the head. The related organ to this chakra is the brain and the endocrine gland is the pineal gland. It has a very calming effect benefits those with stress or sleep problems.
Associated problems: depression, Parkinson’s disease, mental disorders, confusion and dizziness, migraines. It is even said to have an effect on cellulite!
Indigo relates to the brow chakra or third eye which is at the centre of the forehead. The related organs are eyes, lower head, and sinuses. The endocrine gland is the pituitary gland. Indigo is a sedative colour.
Blue relates to the throat chakra and the endocrine gland is the thyroid gland. Blue is a calming colour but not as sedating as Indigo.
Green relates to the heart chakra. The gland is the thymus gland.
Green is a balancing colour, in the middle of the visible spectrum.
When a therapist comes to the end of a colour therapy treatment they will often use green as a balancing colour.
Green is the colour of balance and harmony. It is therefore useful in times of stress and trauma. It has positive stress management, removes blockages, swellings, and congestions. It is used for general pre-treatment of the skin with acne, coupe rose or neuro-dermatitis and psoriasis. Green calms irritated skin.
Yellow relates to the solar plexus chakra. Yellow is a warm colour and has a stimulating effect and supposedly aids concentration. It stimulates the intellect.
Orange relates to the sacral chakra situated in the lower abdomen.
Orange is stimulating, energising and warming. It is supposed to be good for creativity. Orange can aid digestion. Orange stimulates the stomach, thyroid gland and the lungs. It supposedly promotes joie de vivre and optimism!
Red relates to the base chakra at the base of the spine. Red is also a ‘warm’ colour. It is stimulating and energising and therefore helpful for tiredness and lethargy, and to stimulate low blood pressure.
From the above I think we would all recognise some of these basic colour / mood associations – blue for calmness, red for excitement or anger, and so on, but the spa therapies go further to try and treat ailments. This is something that is difficult to prove scientifically but the benefits can be experienced without necessarily scientific proof.
Quality of light in the built environment for health and well being
So far we have considered scientific and holistic treatments with white light and coloured light for various physical and psychological ailments. But the general architectural environment of the hospital, spa, or home is also extremely important in the process of recuperation and continued wellbeing.
In the first instance the availability of natural daylight and sunlight and their interaction with the building design is critical. We know natural light provides the optimum light for healing and well-being purposes for all types of ailment as it has all the colours of the spectrum. Therefore it is essential that this is well considered in the architectural design of hospitals etc.
Ultraviolet radiation from the sun will lower blood pressure, reduce cholesterol levels, reduce blood sugar levels, increase cardiac output, increase the oxygen content of the blood and can strengthen the immune system. This explains why sunlight has been used in medicine for thousands of years.
The Romans believed in the prevention of disease and built with that in mind. Under Roman law there were rights to direct sunlight and Roman architects built for the sun. Exposure to sunlight and sun-bathing was considered good for health and houses and public baths were arranged for this.
Physicians in ancient Greece and Rome accurately described what is now known as mood disorders. They called the emotion associated with gloom and darkness ‘melancholia’ and recommended exposure to the sun as a treatment.
In recent times studies in hospitals have shown the benefits of sunlight. One study in 2005 showed that sunlight in a hospital room affected both the pain level patients felt, and the amount of medication they needed to cope with it. A group of patients recovering from spinal fusion surgery did so in wards that were either on the bright side or the dim side of the ward units in a university hospital in Pittsburgh. Patients with the greater sun exposure reported they experienced less stress and pain both straight after surgery and on discharge from hospital. And they needed 22 per cent less medication each hour to control the pain.
Records on recovery after a cholecystectomy (a common type of gall bladder surgery) of patients in a suburban Pennsylvania hospital between 1972 and 1981 were examined to determine whether assignment of a room with a window view of a natural setting might have restorative influences. Twenty-three surgical patients assigned to rooms with windows looking out onto a natural scene had shorter post-operative hospital stays, received fewer negative evaluative comments in nurses notes and took fewer potent pain killers than twenty-three matched patients in similar rooms with windows facing a brick building wall. (R. S. Ulrich).
In the early nineteenth century doctors began to re-arrange their buildings to take advantage of sunlight therapy. Leading architects of the day began to take up these innovations and formed the basis for what became known as modernism. With new methods of construction and building materials architects were able to erect large framed structures with wide open spaces and large areas of glazing. This allowed for significant amounts of daylight penetration and visual linking of interior and exterior spaces. Le Corbusier, who was apparently a keen sunbather, incorporated sunlight purposely into his designs, for example at The Villa Savoye and L’Unite d’Habitation. And Mies van der Rohe also incorporated the use of sunlight and daylight into his architecture, for example at the Tugendhat Villa in Brno.
When it comes to a hospital environment lit with electric light there are some basic techniques which can support patient comfort and provide a positive environment within which to recover.
For example enhancing visual comfort with indirect or well controlled light to avoid glare; using softer warm white light where possible rather than harsher cool white fluorescent light; avoiding direct view of light sources, normally fluorescent; introducing visual interest through accent lighting on artwork or interior decoration to reduce the overall clinical effect of the interiors.
In contrast to hospitals, health spas are purposely designed for maximum visual comfort and relaxation and recuperation possibilities. Techniques such as low ambient light levels combined with visual interest accent effects, using warm coloured, high colour rendering halogen light. The use of indirect light and minimal ceiling lighting, combined with light integrated into furniture, walls, pools and water features etc. combine to produce a luxurious environment of layered lighting effects to maximise feelings of wellbeing.
So we can see that there is indeed so much that technical and creative use of light in its various forms can bring to the promotion of health and wellbeing. Lighting techniques which were being used in ancient Rome, Greece and Egypt are rediscovered, re-invented, and developed for today’s increased interest in holistic medicine and appreciation of high quality lit environments to promote general well being. No doubt this subject will develop further with more research, and the potential of both natural and electric light will be harnessed more and more.
Therapeutic Effects of Light in Humans: Joan E Roberts PHD, Fordham University.
View Through A Window May Influence Recovery From Surgery:
R.S. Ulrich (Roger) of University of Delaware.