You may have heard people talk about bright light therapy and how it has helped them deal with specific issues in their lives. Hearing these “success stories” has probably aroused your interest in learning light therapy and has given you the urge to try it yourself. Here are some things to know before anything else.
This certainly ancestral technique, at least already attested in early civilizations, uses light rays for care. We will expose its origins, its principles, the means of putting it into practice, and its functioning, its indications and counter-indications, and references.
I – Origin of Bright Light Therapy
The therapeutic use of natural light in medicine dates back to the end of the 19th century. Its remarkable effect on the stimulation of the immune system and the fight against infections led to the development of the first light therapy techniques, rewarded in 1903 by the Nobel Prize in Physiology or Medicine awarded to the Danish doctor Niels Ryberg Finsen.
II – What Is Bright Light Therapy?
Bright light therapy is a proposed psychiatric treatment for depression, circadian rhythm disorders, and insomnia. It consists of exposing the eyes to the light of intensity and specific light spectrum close to sunlight.
In simple terms, bright light therapy is a process used to treat a range of problems through specific and measured exposure to light.
There is no lasting risk of using light therapy. You may experience some side effects when you start the process because your brain adapts to the treatment. These side effects may include headache, nausea, eye strain, and irritability. They are usually quite light and will stop bothering you after a few days of light cure.
III – Different Types of Light Therapy
Light therapy consists in exposing each day to white artificial light, called “broad spectrum”, imitating that of the sun or whose qualities would be as close as possible to those of the sun. Called also phototherapy, this therapy involves exposing the face, but also other parts of the body, to light.
Its goal is primarily to treat disorders associated with disturbances of the internal biological clock, such as seasonal depression.
But the light has other properties, other benefits, which have been used in the history of medicine: convalescence, healing, immunity … Moreover, the light colors other than white also made its evidence for different health problems. In this case, color filters are used on the white lamp.
IV – How Does Bright Light Therapy Work?
Knowing what light therapy is can be helpful, but it’s even more helpful to understand how it works.
The first thing to know is that the protocol is conducted using what is called a light therapy lamp. These emit an intense light source, intended to recreate the feeling of natural light from the outside. One thing to keep in mind when looking for effective treatment, however, is that you want to be sure that the lamp you are going to acquire has enough UV filters.
The light that is emitted will act directly on your brain to regulate functions such as your mood and your sleep patterns and behaviors. So you can expect to be overall happier and sleep better!
Note: Light therapy may be considered a mild medicine that acts on the secretion of melatonin. This sleep hormone is synthesized by the pineal gland (or epiphysis, which is in the brain), and is supposed to be produced during the night (in the dark). In the case of dysfunction of this mechanism, the biological clock of the body is out of order. However, the light produced by the light therapy lamp, arriving at the retina, will cause a reaction of the epiphysis, which will resynchronize this biological clock by inhibiting the production of melatonin, which will promote waking.
V – What Are the Main Principles of Bright Light Therapy?
Bright light therapy is part of the family of phototherapies that use certain light sources (intensities and colors, laser, etc.), sometimes combined with photosensitizers, to treat all kinds of diseases, especially skin diseases. (psoriasis for example) .Light therapy is especially applicable to disorders associated with the disruption of biological rhythms, the best known of which is seasonal depression.
*** The internal biological clock, a powerful control center
By penetrating into the body through the eyes, light plays a fundamental role in the regulation of circadian rhythms, that is to say, those which are spread out over a period of about 24 hours (wake-sleep, variations in body temperature and hormonal levels, meals, etc.). These rhythms, which are managed directly by our internal biological clock, are called endogenous. However, many of them may not last exactly 24 hours. They synchronize with external environmental clues, including daylight, in order to maintain the right pace. The light, therefore, participates in the constant regulation of our internal clock. This one also controls other more or less long biological rhythms (the induction of menstruation in women, for example).
If the rhythms that are subject to our internal clock are no longer synchronized with the day and the night, we feel disturbing symptoms.
The most glaring example is the jet lag experience that makes us sleepy during the day because our endogenous rhythms are convinced it’s nighttime. Depending on the signals sent by the internal clock, the body can secrete the sleep hormone (melatonin), day rather than the evening. Depending on the case, we will be able to “put the clock back on time” by exposing ourselves to the light, at a specific moment of the day, and thus make “advance or retreat” its internal clock. Taking melatonin, also at the appropriate time, can also help restore the internal clock setting.
On the other hand, when light enters the eye, it is transformed into electrical signals that, sent to the brain, act on neurotransmitters. One of these, serotonin, often called the “happiness hormone,” regulates mood and governs the production of melatonin, responsible for wake-sleep cycles. Some scientific research indicates that the metabolism of melatonin is disordered in people with seasonal depression. In fact, an abnormally high level of melatonin has been observed during the day, even if exposure to light would reduce its production.
But bright light therapy also has other applications and benefits:
– It activates cell growth
– It improves the immune system
– It stimulates the healing process of the whole body
VI – How to Use Light Therapy?
Light therapy can be practiced either in a medical setting by therapists (doctor, psychiatrist, neurologist, naturopath, etc.) or at home. If sessions are scheduled, the approach must be personalized, and a schedule must be established taking into account the hourly and weekly constraints of each patient, the time of year, the possible wearing of corrective lenses or ophthalmological disorders.
It is also possible to buy your own lamp and practice sessions at home. The exposure time depends on the intensity of the lamp (half an hour for a 10,000 lux lamp). Then you have to sit about thirty centimeters in front of the lamp, preferably in the morning when you wake up.
VII – What Are the Indications of Bright Light Therapy?
Light therapy is especially effective in combating seasonal depression. Nevertheless, light therapy also makes it possible to treat:
– depression in the elderly and after childbirth (baby blues)
– Premenstrual syndromes
– certain forms of eating disorders
– certain cutaneous pathologies
– certain neurological pathologies (multiple sclerosis, Parkinson’s disease, etc.).
Bright light therapy also makes it easier to readjust following a jet lag.
VIII – Light Therapy: Are There Contraindications?
Professional light therapy is safe because the lamps are specially designed to filter out infrared and ultraviolet rays that may be harmful. There are nevertheless several contraindications, namely:
– taking a photo-sensitizing medication
– psychiatric illness, including autism
– an ophthalmological pathology such as cataract, glaucoma, retinopathy, etc.
Note that to perform sessions at home, it must be equipped with a lamp of quality and respect the standards in force.
IX – How Is a Bright Light Therapy Session Going?
*** Where to perform a session?
A session is generally done by making an appointment with a specialized therapist, sports doctor, naturopath …
*** Running a light therapy session
To benefit from bright light therapy, one must expose oneself daily to light with a defined spectrum and intensity. The luminous intensity must be greater than 2,000 lux in order to act effectively. For comparison, the brightness of a well-lit office is 300 to 500 lux and that of a fully sunny day can exceed 100,000 lux. The clinically recommended and recognized standard is a 10,000 lux light exposure at eye level for 30 minutes each day.
For specific care on a body area, the exposure is usually 3 minutes in white light, or for colors:
3 minutes of the main color followed by 30 seconds of the complementary color (for example, red then green, orange than blue, then yellow purple) or 3 minutes only for the indigo color that is balancing. For children under 7 years, the duration is 1 minute and 10 seconds of the complementary color.
There is currently a consensus to recommend treatment in the morning rather than in the evening. For the treatment of children and adolescents (who may also be suffering from seasonal depression), the duration should be less, that is to say, about 15 to 20 minutes per session, but it is important to be vigilant about possible symptoms of agitation caused by bright light therapy. If you think you are suffering from seasonal depression, it may be best to talk to your doctor to make a diagnosis.
In general, the results are felt as early as the first week of treatment, but 4 weeks of use are usually required before observing a clear clinical response and measurable biological changes. Light therapy is effective in about 2 out of 3 patients with seasonal depression. In their case, the symptoms are reduced by 50% to 80%. This rate is comparable to that of antidepressants, but light therapy causes fewer side effects and is less expensive.
X – Physiological Activity of Light and Type of Light Used
By its inhibition of the secretion of melatonin, the light allows an improved awakening and a better vigilance. It regulates the biological clock and improves the synchronization of biological rhythms, which will result in better shape and better vital energy. It stimulates the regions of the base of the brain and increases the level of serotonin (neurotransmitter) which has an antidepressant and appetite-regulating effect.
The treatment starts in September or October and continues until spring. Some people may also feel the need in the summer if it is gray for several days in a row. The most affected individuals may experience a return of symptoms only after 2 or 3 days of stopping. So, when the beautiful days of spring are coming, it is better to reduce its exposure gradually.
This is the solar light spectrum but without ultraviolet (UV) that is harmful to the skin and cornea. The unit of illumination is lux. The dose recommended by specialists in the field is 10,000 lux at a 45 cm distance for 20 to 30 minutes in the morning. The color temperature of the light is usually 4,000 K.
Usually, a mercury lamp is used but other technologies exist.
On the other hand, some specialists have reservations about the new light-emitting diode technology that uses shorter wavelengths of a bluish color. It appears that blue light used in the long term could cause apoptosis (cell death) in the retina. So far, only studies in animals have been able to show such an effect. However, it is safer to use light therapy lamps that have proven effective and have been used for more than 20 years without damage in the long term.
The heat released by a white light lamp is the same as that of a regular lamp. When using such an apparatus, the higher the amount of lux, the shorter the treatment. For example, you have to expose yourself for 30 minutes with a lamp that emits 10,000 lux, and 60 minutes if it emits 5,000. The further you stay away from the camera, the longer you have to extend the exposure.
XI – Light Therapy at Home
Although some clinics offer the service, bright light therapy treatments are usually done at home. Lighting fixtures, orthopedic appliances, and pharmacy stores provide lamps that are just as effective as those used in the clinic. Make sure that the device does not emit UV light and that the light intensity reaches about 10 000 lux (or 2500 lux in the case of LED lamps). The light field must also be large enough so that you are not confined to a small space during the show. During a session, nothing prevents them to continue their normal activities: reading, work, meals, television, etc., to the extent that the face remains bathed by the light.
There are also low light-emitting masks that apply directly to closed eyes during sleep. They were designed, among other things, to be worn by plane, but have been the subject of relatively few studies.
When treatment is prescribed by a health professional, some insurance companies reimburse the cost of the devices. You can encourage your practitioner to contact the insurance company directly to claim that a light therapy lamp is cheaper in the long run than taking an antidepressant while being as effective.