Light therapy

Everything you need to know about light therapy

Light therapy and its benefits

In which cases should a light therapy lamp be used?

What are the effects of light therapy on our brain?

How to properly use a light therapy lamp?


    atmosphere, light therapy, dayvia

    Light therapy , as its name suggests, is treatment with light. This technique aims to effectively treat disorders of the circadian cycle, in other words "healing with light". This alternative medicine consists of exposing your body to as much light as possible through lamps specially designed to dispense light that conforms to an optimal wavelength.

    Light therapy is part of the large family of phototherapies, not to be confused with other treatments such as: chromotherapy (or chromatotherapy) which will use colored lights to treat specific pathologies, of the body or the face but mainly cutaneous, or still heliotherapy, which will use natural sunlight.

    sleep disorder, light therapy, dayvia

    There light therapy lies in the repeated exposure of the eyes to a source of artificial white light, called "broad spectrum" reproducing sunlight. The main difference with sunlight is the absence of any harmful rays (X-ray, UV or IR).

    This natural non-drug method is the optimal choice for the treatment of seasonal depression, sleeping troubles or even non-seasonal or postpartum depression.

    It should be noted that light plays a fundamental role in the regulation of our biological clock and in the secretion of the hormones involved.

    Many international studies show that light therapy helps to regain energy, form, ability to concentrate and good mood like that felt when you sunbathe in the summer.

    What is the principle of light therapy?

    light therapy principle, Dayvia

    There light therapy relies on the effect of exposure to light on receptors located in the retina. Indeed, it was discovered in 2002 that there were photoreceptors on the retina, the melanopsin ganglion cells. These cells are involved in the “non-visual functions” of the eye are activated by light, but are not involved in vision.

    These cells are therefore sensitive to a specific light close to that of the sun and the intensity of the sensitivity will depend on:

    • Light intensity
    • Exposure time
    • The show time
    • The light wavelength (color)
    • The luminous history

    That said, melanopsin ganglion cells exhibit optimal sensitivity to lights with wavelengths between 475 to 500 nanometers.

    In the morning, when light enters the eye, it activates the photoreceptors, these are connected to the structures of the brain and then transform the visual signal into an electrical signal which is sent, in turn, via the optic nerve to the regulator of our biological clock (the suprachiasmatic nucleus). This will then interpret the signal and command, via the pineal gland, to stop the secretion of melatonin (the sleep hormone) and trigger the production of serotonin and cortisol (hormones of wakefulness, happiness and anti-stress energy).

    serotonin and melatonin
    melatonin and serotonin2

    Each evening, with the drop in light intensity, the mechanism is reversed.

    Melatonin is produced in our brain when the secretion of serotonin and cortisol is stopped.
    The optimal functioning of this cycle, called circadian cycle . It is essential to ensure an excellent psychic and emotional balance.


    Why use a light therapy lamp?

    Each evening, with the drop in light intensity, the mechanism is reversed. Melatonin is produced in our brain when the secretion of serotonin and cortisol is stopped.

    The optimal functioning of this cycle, called the circadian cycle.

    It is essential to ensure an excellent psychic and emotional balance.

    • More irritability and anxiety
    • A gloomy mood
    • A lack of energy
    • sleep disorders
    • Chronic fatigue, etc.

    These are the main manifestations of the winter blues.

    If these symptoms occur for 2 to 3 consecutive years, then it is seasonal depression .

    Seasonal depression, Light therapy, Dayvia

    Research shows that in people with seasonal depression , the melatonin (sleep hormone) secretion mechanism is often disrupted. We then observe in these people a particularly high level of melatonin during the day, which explains the fatigue felt during the day.

    In the morning, light therapy stimulation of the retinal ganglion cells (non-imaging photoreceptors) blocks the transformation of serotonin into melatonin during the day.

    These light therapy sessions will also allow a "reprogramming" of the biological clock so that melatonin will be naturally and normally secreted in the evening, when the light decreases, to promote the sleep phase.

    What are the benefits of light therapy?

    Benefits of light therapy, Dayvia

    Exposing your body daily to artificial white light would have

    many beneficial effects on the body.

    Mood, energy, morale, healing or immunity, the benefits of light have been recognized for many years. It plays a key role in the proper functioning of the body's biological functions.

    This is why an additional supply of light using light therapy lamps or glasses in periods of low light is often recommended.

    Dayvia is positioned as the French specialist in light therapy and offers a range of products with medical approval that ensures its users an optimal level of efficiency and safety.

    Seasonal depression is a frequent pathology, long underestimated and therefore often underdiagnosed. This is how Dr Eric Charles, a psychiatrist in Limoges, believes that the majority of people who suffer from it are at best taken care of for a depressive episode without taking into account this seasonality or at worst that they go through autumn and winter. winter dragging their pain and suffering without any medical or psychological care.

    Light therapy research, Dayvia

    In 2015, he then published a book entitled “To Each his own rhythm” (Editions First), in which he presented a study carried out among general practitioners in Limoges and its agglomeration. They found that around one in seven people who visited their GP during the winter, for whatever reason, had seasonal affective disorder.

    In France, each year, more than 500,000 people could present this type of seasonal disorder.

    Most of the time, the seasonal depression is treated with antidepressants, but these are not necessarily the most effective.

    • mood disorders
    • Non-seasonal depression
    • bipolar depression
    • Postpartum depression
    • Neurodegenerative pathologies such as Alzheimer's or Parkinson's

    Light therapy has consistently been cited as one of the best non-drug therapies for insomnia disorders.

    But be careful, the choice of the lamp is essential for obtaining convincing results. Dayvia products have CE medical approval, they are regularly tested and approved by independent authorities.

    1. Seasonal depression


    Light therapy has consistently been cited as one of the best non-drug therapies for insomnia disorders.

    But be careful, the choice of the lamp is essential for obtaining convincing results.

    Dayvia products have CE medical approval, they are regularly tested and approved by independent authorities.

    2. Sleep/wake rhythm disorder

    sleep rhythm disorder, light therapy, Dayvia

    Regular use of a light therapy lamp can reset the internal clock of the patient who has phase shifts or insomnia.

    If the patient is in phase advance: he falls asleep very early (5 p.m. for example) and also wakes up very early (for example 3 a.m.). A light therapy session around 5 p.m. will stimulate the secretion of serotonin, block melatonin and therefore delay his sleep phase.
    Conversely, if the patient is late in the phase: he falls asleep late and wakes up late. A morning light therapy session will reset his sleep phase and he will fall asleep earlier in the evening.
    For patients suffering from "Bad sleep": a morning session of light therapy will improve their sleep while avoiding the side effects of sleeping pills (morning drowsiness, reduced memory and decapitation of phases III and IV of sleep (recovery phases), decreased libido, risks of addiction and dependence).

    Made in France, Dayvia

    There light therapy has consistently been cited as one of the best non-drug therapies for insomnia disorders.

    But be careful, the choice of the lamp is essential for obtaining convincing results. Dayvia products have CE medical approval, they are regularly tested and approved by independent authorities. Compliance with these strict regulations guarantees the user an effective and safe product.

    And in addition, they are made in France

    3. Disorders caused by shift work

    (Night work)

    female doctor computer
    When working at night or late afternoon, the time of exposure to sunlight decreases drastically. This is very common among shift workers who also find it difficult to spend time outdoors between shifts.

    As exposure to light is our primary synchronizer, lack of light has a real impact on the overall functioning of our internal clock. Without light, there is no synchronization and therefore no energy.

    Light therapy will therefore contribute to “setting up” the body in daytime mode, by boosting the secretion of good hormones and by setting the internal clock with the schedules of life.

    4. Jet lag or jet lag

    jet lag airport woman

    During a trans-meridian journey of more than 3 time zones, the biological clock is projected in less than 24 hours on a completely different new schedule of light and dark. Although quite flexible, the circadian clock does not have the ability to adapt so suddenly, and we quickly feel an internal disorder set in: the famous symptoms of jet lag.

    Dissipated after a few days, these symptoms can become very disabling for people who travel very regularly.

    To compensate for the shift in the day-night schedule between the place of departure and the place of arrival, light therapy will act like an artificial sun, which allows the internal clock to gradually shift over a few days.

    5. Mood Disorders

    young woman tired mood

    The effects of light on mood were already described in antiquity and from the first medical descriptions. Forty years ago, neuroscience led to a renewed interest in light therapy. The first observations noted that the modification of biological rhythms could have an antidepressant effect and that light modified these rhythms.

    Very quickly, the clinical confirmation of the antidepressant effects of light therapy was confirmed, particularly in the treatment of seasonal depression and then of unipolar depression. Neurosciences have subsequently also made it possible to better define the real effects of light and the phototransduction pathways involved in mood regulation. These studies validated the fact that there was an action on mood via an effect of light on circadian rhythms .

    4. Postpartum depression

    postpartum depression woman baby

    There postpartum depression is a mood disorder that affects about 10-15% of women after childbirth. Prompt diagnosis and treatment of symptoms is crucial for the well-being of mother and infant. A majority of women reject treatment with drug therapy, especially during the breastfeeding period, because they are worried about the possible effects of drugs on the developing infant. The use of light therapy can then represent an appropriate and non-pharmacological treatment.

    5. Neurodegenerative pathologies (Alzheimer's, Parkinson's)

    Neurodegenerative pathologies, light therapy, Dayvia

    There Alzheimer's disease is mainly characterized by a phase of dementia.

    In medical vocabulary, the state of dementia results in a progressive deterioration of cognitive faculties and loss of memory, a tangible element of the degradation of the aptitudes of individuals suffering from Alzheimer's.

    According to certain studies, light therapy could reduce the amyloid-β protein load in the brain, which is partly responsible for the cell degeneration characteristic of Alzheimer's disease.

    In the specific case of Alzheimer's disease, researchers have observed that carrying out light therapy cures can restore memory and cognitive abilities as well as improve the quality and duration of sleep.

    The bright nature of living spaces would also exert an influence on the levels of aggression and anxiety of patients with dementia.

    For Parkinson's disease, light therapy acts mainly on non-motor symptoms such as insomnia, depression or fatigue.

    Light therapy also brings an interesting action in the prevention of the disease. Thanks to its action on the regulation of circadian rhythms and sleep disorders, light therapy would reduce risk factors.

    Recent studies have demonstrated a correlation between lack of sleep and an increased risk of developing dementia. This is demonstrated by a study conducted by the French National Institute of Health and Medical Research (Inserm) and the University of Paris, in collaboration with University College London (UCL).

    What are the effects of light therapy on our brain?

    Effects of light therapy, Dayvia

    Under the effect of light, the connectivity of the brain, the way in which the different areas exchange with each other is modified. Light therapy establishes an optimal dialogue between the amygdala and the hypothalamus. The amygdala is involved in the modulation of emotions and the hypothalamus, located in the subcortical brain, is involved in the functioning of mood, motivation, sleep (remember that it is the seat of the clock biological), appetite, thermoregulation... Directly linked to the pituitary gland, which secretes a whole series of hormonal precursors (in particular the precursors of sex hormones), the hypothalamus has an impact on all our vital functions. The quality of light therefore directly influences the way our brain processes our emotions.

    Who can perform light therapy?

    Light therapy is safe and has few contraindications. It can be performed without medical advice by anyone wishing to treat a pathology among those described above, without distinction of age (excluding young children), sex, skin color.

    For an effective session at home, the ideal is to use a CE medical device certified light therapy lamp or glasses with a power of 10,000 lux or approximately 480 nanometers for 30 minutes, preferably in the morning. For light therapy lamps to be placed or hung on the wall, the ideal distance between the light source and the eyes is 30cm.

    Studies have shown that light therapy can be practiced safely, however, before starting your treatment, please consult your doctor if:

        • You suffer or have suffered from depression
        • You are hyper sensitive to light
        • You suffer from an eye disease such as cataracts, glaucoma, …
        • You suffer from mental disorders
        • You are undergoing treatment with psychotropic or photo-sensitizing drugs

    If you experience any problems (eg headaches or eyestrain) following the use of a light therapy device, please inform your doctor.

    For people with bipolar or manic-depressive disorders, light therapy should be used with caution due to the possible risk of triggering a manic episode. Prior medical monitoring is therefore recommended.

    When to use light therapy?

    use of light therapy, Dayvia

    Researchers and doctors agree on the fact that the light therapy session should preferably be carried out in the morning rather than in the evening, except in the case of phase shift or shift work.

    For children and adolescents, the exposure time should be reduced to 15 - 20 minutes maximum.

    In general, the first effects are observed from the first week of treatment but very often, 4 weeks are necessary to observe measurable biological changes.

    On average, symptoms can be reduced by 50 to 80% depending on the patient. This is a rate comparable to anti-depressants, but light therapy has far fewer side effects and is much less expensive.

    Treatment should begin as early as September or October and continue until spring. Particularly sensitive individuals may experience a return of symptoms only a few days after exposure has ceased. In this case, as soon as the good weather arrives, it is recommended to reduce the duration of the sessions gradually.

    How to position a light therapy lamp?

    position light therapy lamp, Dayvia

    To practice the light therapy , it is essential to acquire a perfectly adapted medical device, namely a lamp or light therapy glasses with the CE marking followed by 4 digits (CE0459 for Dayvia). The SlimStyle or 072 light therapy lamp allows you to perform your session in the morning at breakfast and to benefit the whole family.

    For the treatment to be effective, the lamp must be positioned so that the light can reach the eyes. It is not really necessary to fix the light source, it is enough that it remains in the visual field. However, the eyes must remain open during the session so that the rays can reach the retina and transmit the light influx to the brain.