The sun: the fountain of life

Sunlight is life’s most basic requirement. Nothing would exist without it, and lack of adequate sunlight quickly drains our vitality and energy. The volume of light is highest in summer, when the days are longest and brightest.

The amount of light is measured in lux, the international unit of illuminance. One lux corresponds to the volume of light produced by one candle measured one metre away. On a normal summer’s day, the volume of sunlight is around 50 000-100 000 lux outdoors. In an office, the volume of light is 300-500 lux. In November, the illuminance can drop to 500 lux outdoors,

whereas the illuminance produced by normal indoor lighting is 10-100 lux. This is a thousand times less than the volume of natural light on an average summer day.

As the autumn advances, the shortening of the days is a common cause for winter blues. Around 12 percent of Finns suffer from SAD (Seasonal Affective Disorder). The less severe form of SAD is winter blues or subclinical SAD, which is also much more common, with around 27% of Finns suffering from it.

Based on user experience, regular bright light therapy helps maintain good work flow. Especially office workers and their employers have become aware of the benefits of bright light therapy.

Shift workers have also discovered that bright light therapy helps balance their irregular circadian rhythm. Correctly timed bright light therapy can also significantly speed up recovery from jet lag.

A bright light device provides summer morning light throughout the gloomiest winter months.

The body’s circadian rhythm is regulated by melatonin, a hormone produced by the pineal gland. The body produced this hormone normally during the night. Melatonin is a bit like the body’s own sleeping pill: when there is melatonin in the body, the person will feel tired.

Morning light is the strongest stimulus outside the body that regulates the circadian rhythm. Of all the factors that regulate the circadian rhythm, the function of melatonin is best understood. Research shows clearly that light strongly affects the secretion of melatonin.

When waking up on a summer morning, light stops the production of melatonin. In winter, however, it is still dark when it is time to get up. If melatonin is produced in the morning after waking up (as is the case in the dark season, i.e. in the autumn and winter), the body clock goes out of sync, which affects the circadian rhythm. This leads to the “winter blues”, which normally last from October to March. Symptoms include craving for carbohydrates and sugary foods, difficulty waking up, excessive sleepiness, lethargy, and tiredness during the day. So the shortage of daylight hours is the main culprit behind the winter blues.

Summer morning light - bright light therapy - is needed on autumn and winter mornings to stop melatonin production and keep circadian rhythm in sync.

When the production of melatonin is stopped with bright light therapy in the morning, melatonin production will start at the right time in the evening. Bright light therapy is most efficient in the morning right after waking.

Innolux bright light devices are easy and efficient to use.

Innolux bright light devices can be used in bright light therapy, which efficiently compensated for the lack of natural light during winter months. Innolux bright light devices are medical devices certified by Det Norske Veritas, which guarantees their efficiency and safety of use. The devices meet all requirements set for good bright light therapy, without any side effects such as headache or tired eyes.

For the first two weeks, bright light therapy should be used daily, and later on five times a week throughout the winter. The benefit of the therapy can usually be seen within a week: the user will feel as lively and energetic as in the summer.

Not all lights are suited for bright light therapy, as the minimum illumination requirement for a bright light device is 2 500 lux. The recommendation is to start with two hours of bright light therapy a day. The daily duration of the therapy can later be shortened to half an hour a day. The therapy is most efficient in the morning between 6 and 10. In the evening, bright light therapy can cause difficulties falling asleep, and so it is not recommended after 6 pm.

Depending on the type of bright light device, the correct distance from the light is 40-145 cm. This means the distance of the face from the device. The closer to the light you are, the more efficient and therefore shorter each therapy session can be. There is no need to look at the light directly, as long as it is stays in your line of vision. Bright light therapy does not interrupt any of your everyday activities, as you can read, eat, work, and watch TV during it.

Bright light research

Bright light therapy has been studied in Europe and North America for nearly 30 years. Bright light therapy has been studied widely in Finland also.

Research has yielded promising results in the treatment of depression and sleep disorders when medical treatment is not an option (as in case of the Parkinson’s disease and depression during pregnancy). The results of bright light therapy have been encouraging also in medical conditions with clearly seasonal patterns or sleep disorders.

We have collected the latest international research results, from the National Institutes of Health in the United States:

New research results have been gained of the benefits of bright light therapy in preventing daytime exhaustion and tiredness with SAD and subclinical SAD patients.  Research shows that bright light therapy improves overall wellbeing. Read more about the research.According to a new study, bright light therapy helps SAD patients after as little as one session. Read more about the research.

The study, on the positive impacts on bright light therapy on women suffering from depression during pregnancy, is especially promising, as bright light therapy has no side effects. Read more about the research. New research insights have also been gained on the benefits of bright light therapy in treating non-seasonal depression in teenagers. Read more about the research.