Light Therapy Benefits

Treatment of S.A.D through Light Therapy

For thousands of years people the world over have revered the sun as a great healer; some ancient cultures even worshipped the sun. There is no doubt that the sun plays a very important role in our daily lives. We feel energized after spending time in the sun, and the winter can leave many of us feeling drowsy and less inclined to physical activity. In the tropics the light is sufficiently intensive and available for a long period of time and free of charge the whole year round. In the northern part of the world, however, this is not the case. This is firstly due to the fact that the autumn and winter are relatively long and dark and secondly because of our lifestyle. We get up in the mornings surrounded by artificial light; we go to work at dawn, spend the day in an intensity of light of approximately 500 lux, return home at dusk and often spend the evenings sitting in a dim room watching television. Many people are very sensitive to this period of relative darkness, and experience many unpleasant symptoms as a result of this lack of light.

Seasonal affective disorder light therapy (using Seasonal Affective Disorder Lamps)  has been proven effective in over 85% of diagnosed cases, with exposure from 30 minutes to several hours per day to very bright light, at least 10 times the intensity of ordinary domestic lighting. The aim is to provide bright summer light to stimulate a change in the levels of chemicals and hormones which affect the mood (see Causes).

Ordinary light bulbs and fittings are not strong enough. Whereas the average home or office lighting deliver an intensity of 200-500 lux. The recommended exposure time to bright light depends on the power of the lightbox. An effective dose is 5,000 lux per day, given as 2,500 lux for two hours or 10,000 lux for 30 minutes each day, during the autumn and winter months (where lux is a measure of the intensity of light).

LUX- is unit to measure light intensity that actually reaches the target. Lux varies depending upon how far away the target is from the light source and other environmental factors such as wall colour, reflectors, etc.

Under a sunny sky on the beach
100,000 lux
Typical bright light therapy product for SAD treatment
10,000 lux
In spring, outdoors, a few minutes after sunrise
10,000 lux
In a very well lit office
500 to 1000 lux
Home lighting
300 to 500 lux

Sad light therapy treatment should be used daily in winter (and dull periods in summer), starting in early autumn when the first symptoms appear. It consists of sitting 2-3 feet away from a specially designed light box (whether it would be an Ultra High Powered, High Powered, Ultra Compact, Desktop, Medium Powered, Lower Powered or Combination model) wearing a Light Visor, or waking up to Natural Alarm Clock. Allow the light to shine on the eyes. While getting your light treatment carry out normal duties; eating, writing, reading, etc. It is not necessary to stare at the light during the session, but keep in mind that the more photons that reach the retina, the faster the session will be.

Light therapy is very similar to natural daylight and it won't harm your eyes, unlike strong ultraviolet (UV) light. You should never use homemade light units, such as tanning lights or beds for light therapy. The light given off by these units is high in UV rays and can harm your skin and eyes.

Treatment is usually effective within 3-4 days and the effect continues provided it is used every day until spring – when there are more daylight hours. Sun glasses, tinted lenses, or any device.

Light box treatment can be done in your own home or office. Light boxes aren’t generally available on the NHS but you can buy or hire one through us. 

Understanding the impact of daylight on your health

The human body uses light cues, such as those provided by the sun, to time certain functions.

Properly timed rhythms regulate mood, sleep, wake, appetite, digestion and energy. These daily internal cycles called ‘Circadian Rhythms’ sometimes fall out of time, meaning an unregulated body clock, resulting in the symptoms of Seasonal Affective Disorder (SAD).

Circadian Rhythm Imbalance - how it causes Seasonal Affective Disorder

Now with our hectic lifestyles, we often miss critical signals from the sun, and our body clocks suffer. Without proper morning light, our body clocks don’t produce the hormones we need to wake up and feel active. When we miss daytime light, we slump and become less productive. At night, we usually stay up hours after dark, causing sleep and mood problems. In fact, how we sleep, how active we are, and how we feel are all regulated by our body clock.

When your body clock doesn’t get the right light signals, you can feel tired, moody, and sluggish. But when your body clock does get the right type of light, your body produces active, energetic hormones and suppresses the negative, withdrawal ones. These hormones will help reset your sleep, mood, and energy cycles, so you sleep better at night and feel great during the day.

Increasingly, light therapy is being used to reset our body clocks - sometimes along with melatonin and sometimes on its own-no matter how or why they've been put off track. Scientists are discovering that light therapy may have potential for treatment of several other disorders in addition to that of SAD.


S.A.D and Winter Blues

Winter Blues is the common name for Seasonal Affective Disorder (S.A.D.), which is a sub-type of major depression. Up to 25% of North Americans have some form of winter blues, and roughly twice as many women as men develop this condition. Most experience symptoms starting between the ages of twenty and forty, but even young children may be affected. Typically the symptoms are depressed mood, losing interest in work or social activities, eating more and weight gain, needing more sleep, feeling lethargic and drowsy. The symptoms start from September to March, December, January, and February are typically the worst months. The further from the equator, the higher the incidence of SAD, due to the shorter winter days. For example, winter blues is ten times more common in the northern states than in the south. Children and teenagers also suffer from winter blues. Symptoms may include grades falling in the winter and rising in the spring, or poor relations at school during winter. Researchers in northern climates have found that as many as 90% of 12-15 year-olds report a lack of energy, depressed mood, or need for added sleep during winter. Both children and teenagers have been shown to respond well to light therapy. Light therapy for winter blues usually consists of 15-60 minutes of light every morning during the dark, depressing winter days. Typically, you will recognize when you've received sufficient light therapy.

Non Seasonal Depression

It has been proven that the use of light therapy for patients suffering from depression is as effective as it is for those suffering from SAD. A recent trial concluded that the benefits of light therapy were felt after only one week, whereas many medications took up to 8 weeks for the benefits to be felt. Also, using light therapy together with medication has superior results to either treatment on its own. 

Clinical Depression

Researchers report that depression is closely tied to circadian rhythm disorders because almost all depression sufferers have sleep problems and feel worse at a particular time of day as well as in the winter. When treated with bright light, these problems improved significantly. Because bright light quickly corrects the circadian imbalance in depression, patients respond to light within a week verses months with antidepressant medications.

The fact that depression is circadian related is further evidenced through a new treatment known as wake therapy. Researchers believe that depression sufferers have unresponsive body clocks. Wake therapy awakens the patient several hours early, which blocks any feedback signals to the body clock when it is most active. This effect œreboots' the body clock, causing it to revert to an active day cycle. With wake therapy, symptoms of depression disappear almost immediately. Wake therapy is only necessary for the first night if used with bright light each successive morning.

This revelation on circadian rhythms and depression has led researchers to conclude, "These common experiences suggest that disruptions in biological clocks may be both cause and consequence of disturbed moods."-- Michael Smolensky, The Body Clock Guide to Better Health. 

Bipolar Disorder

Bipolar Disorder is different than major depression in that it is marked by episodes of euphoria or mania. These episodes can last for hours, days or even months. In almost all cases of Bipolar Disorder, depressive and manic episodes are seasonal. In the Fall and Winter, bipolar sufferers enter a depressive phase, and require increased intervention. Bipolar sufferers also suffer from sleep problems and feel worse at a particular time of day. Because these symptoms reflect a circadian rhythm disorder, doctors have found success by treating bipolar disorders with bright light.

Premenstrual Syndrome (PMS)

Premenstrual Syndrome (PMS) is a combination of physical discomforts and emotional symptoms that happen during the latter half of the menstrual cycle and usually let up during the first few days of menstruation. PMS is marked by low levels of progesterone and serotonin hormones. Researchers believe these hormones may deplete too quickly, and not allow enough time for the body to adjust. During this period, women's body clocks also speed up causing melatonin to be released prematurely and the supply of serotonin to be cut off. This may account for the increased pain, irritability and sleep problems.

Chronic illnesses are also at their worst during PMS. Asthma, depression, diabetes, fibromyalgia, hot flashes, migraines, acne, rheumatoid arthritis, are all affected by this change in hormone levels.

One interesting study showed that close interaction between people can affect their biological clock. In the study, women who lived together, tended to keep regular cycles that coincided with each other. Their menstrual cycles were often affected as well. Close women often have their periods at the same time. With many activities done together, they regularize many biological rhythms, including those of the hormones that affect the menstrual cycle.

Bright Light helps PMS - Women's health researchers discovered that PMS is tied to circadian rhythms. Apparently, the body clock begins to cycle too quickly during the second half of the menstrual cycle, and may be a reason why these reproductive hormones deplete too quickly. Light is known to produce serotonin, the mood hormone lacking in PMS sufferers. Evening light is also the most effective way to slow the body clock down to a normal rhythm. When researchers used light to slow the body clock back down, symptoms of PMS also dissipated. The discovery that light reduces menstrual problems as well as regulates cycles, is encouraging, particularly for women who are seeking natural alternatives:

÷This apparently powerful yet simple and seemingly safe methodology should lead to exciting progress in our understanding of human reproductive endocrinology. Daniel Kripke MD, Head of Chronobiology Research, UCSD.

Premenstrual Dysphoric Disorder (PMDD)

PMDD is a short-term depression, which occurs during the latter part of the menstrual cycle. PMDD is usually associated with more severe symptoms of PMS and interferes with the ability to interact socially. Approximately 5-10% of PMS sufferers also have PMDD. The difference between PMMD and other disorders is that its symptoms generally appear the week prior to menstruation.

There is a strong connection between PMDD and low serotonin. Serotonin acts as a calming hormone. When serotonin levels are restored, many of the more destructive symptoms of PMDD disappear, such as pain, anxiety, irritability, anger and food cravings.

The discovery that light regulates serotonin and melatonin is significant, because these hormones are linked to PMDD. For example, studies show that women suffering from PMS and PMMD not only have low levels of serotonin, but that their body clocks are running too fast. This releases the withdrawal hormone, melatonin, too early, which depletes serotonin reserves and causes sleep problems. Using this special light in the evening will slow the body clock back down and balance natural serotonin levels.

Since light is known to produce serotonin as well as reset the body clock, researchers at UCSD have had success using Apollo's Britewave technology in treating women with PMS and PMDD. Adding light a week before PMS or PMDD occurred, cut symptoms by at least 50%. This was more effective than drugs alone, but relief was even greater when light was used in conjunction with medication, especially for women with severe symptoms. Many women reported complete relief from light alone.

Post Natal Depression

Prenatal and postpartum depressions are depressive disorders that occur during or within a year after pregnancy, afflicting 10% of all women. Prenatal and postpartum depressions are among the most serious mood disorders for women because they impact the health of the fetus and newborn. An expectant mother will not take as good care of herself, which may harm the fetus. Studies also show that depressed mothers don't care for their babies as well as other mothers. They talk less, show less affection and don't' respond as well. As a result, their babies have more problems socially; they withdraw, and are less animated than other babies. Commenting on the long-term consequences,

÷Children of depressed mothers are at increased risk for anxiety disorders in childhood, major depression in adolescence, and alcohol dependence in early adulthood. Furthermore, depressed offspring of depressed parents have a longer duration of episodes, more impairment, more medical problems and receive less mental health treatment. In addition to having more serious and recurrent depression, they are more socially and vocationally impaired. Thus, to reverse these adverse consequences of maternal depression, treatments need to be instituted early in the course of the illness.ƒ

Why expectant and new mothers become depressed - Pregnancy and delivery causes hormone levels in some women to be too low. During pregnancy, the body clock releases hormones that increase the body's ability to deal with the added stress of having a baby. These hormones take their toll though, by depleting reserves of serotonin, the hormone associated with wellness and mood. During the third trimester and just after birth, serotonin levels are as low as those found in people with major depression. This is why over 70% of new mothers experience the œblues,' and 10% suffer from depressive illnesses.

Pregnancy and postpartum depressions affect the body clock Researchers have also noted a strong connection between circadian rhythms and pregnancy related depressions. Symptoms are generally worse in the morning time, and the sleep problems are a result of disrupted circadian rhythms. Since light is known to produce serotonin as well as reset the body clock, researchers at Yale and UCSD have had success using Apollo's BRITEWAVE¾ technology in treating women with pregnancy related depressions. In this case, the specialized light is used in the morning time. News that morning bright light is helpful is important because anti-depressant medication is undesirable during pregnancy and nursing.

Sleep Disorders


Because the circadian rhythm controls the sleep/wake cycle, circadian rhythm disorder often results in insomnia. If there is a pattern to the sleep disturbance, i.e., one consistently wakes up or falls asleep at the wrong time, or if he/she cannot get to sleep at certain times, it is most likely that his/her circadian rhythm is malfunctioning.

The American Academy of Sleep Medicine (AASM) estimates that 25% of all sleep problems are directly related to circadian sleep disorders and several other sleep problems are either caused by or contribute to circadian rhythm disorders. These sleep disorders include late night and early morning, insomnia, interrupted sleep patterns, free-cycling sleep disturbances and irregular sleep disorders. (For specific information on all circadian related sleep disorders, visit the sleep section on this webpage.) The two most common sleep problemsLate night and early morning insomnia are discussed below.

Late Night Insomnia - The majority of people with sleep problems experience difficulty being able to fall asleep. They may only experience a few hours of sleep each night, and feel worse in the morning time. In this case, the body clock is running slower than a normal circadian rhythm (24 hour period). The clinical term for late night insomnia is Delayed Circadian Rhythm Disorder or DCR. DCR sufferers' body clock doesn't 'wake up' until later in the morning or day. They have difficulty getting started in the morning, may feel a bit groggy or down during part of the day, and may experience a second wind later in the evening. Those with DCR are often referred to as night owls, and find it easier to stay up late at night.

With DCR, the daily cycle, or circadian rhythm is running slow, and the pineal gland releases the nighttime hormone melatonin too late, causing sleep to occur later. In the morning, the body clock is still producing the nighttime hormones. This is why it may take several hours to feel active and energetic. Because DCR sufferers don't receive the proper amount of sleep, energy, alertness and ability to function may also be diminished.

Because DCR is the result of a slower circadian rhythm, bright morning light is the most successful means to speed the body clock up and restore circadian rhythms to their normal function. Because DCR disorders vary with individuals, the treatment schedule needs to be adapted accordingly. Apollo provides an effective assessment tool on its website for determining the proper treatment schedule and guidelines.

Early Morning Insomnia - As people age, they tend to have difficulty staying asleep, and usually awaken hours before dawn. Those with early morning insomnia generally tire easily in the afternoon or evening and have little difficulty falling asleep. The clinical term for this disorder is Advanced Circadian Rhythm Disorder or ACR. ACR happens when the body clock is running faster than a normal 24-hour period. Because the body clock is running too fast, ACR sufferers tend to run out of energy before the 'day' or 24 hour period is through. ACR also tends to compress the sleep portion of the daily cycle, causing ACR sufferers often sleep less than 8 hours per night.

Because the circadian rhythm is running fast, the pineal gland releases the nighttime hormone melatonin prematurely, causing one to feel tired earlier in the evening. Since melatonin is released prematurely, the body clock can't sustain a complete sleep cycle, causing early insomnia.

Bright evening light has been shown to be the most effective treatment for ACR. Evening light slows the body clock down to a normal rhythm. This delays the onset of melatonin and sleep, allowing the person to sleep longer and have more energy in the late afternoon and evening.

Jet Lag

Jet lag is the result of one's body clock being out of synch with a new time zone. The symptoms of jet lag are similar to depression, and will persist until the body clock can respond to the new time. Without intervention, this process takes one to two weeks, depending on the distance traveled. Jet lag is easily avoided by using timed bright light to speed up the body clock's adaptation to the new time.

Shift Work

Shift work almost always causes a circadian rhythm disruption, where a person's internal body clock is at odds with the shift schedule. Shift work problems are well documented and range from perfomance issues to accidents and other health problems. Recent evidence shows that shift work may contribute to cancer because working at night in well lit enviornments suppresses melatonin, which acts as a powerful anti oxident. Additionally, proper circadian signaling causes cells to die, and shift workers may not be receiving these needed signals. As a result, mutated or deformed cells continue to grow when they otherwise would be destroyed.

Shift workers can easily adapt their body clocks to work within the shift schedule's requirements by using a light therapy protocol. Using this protocol will increase work performance, improve sleep and off-shift scheduling problems, as well as decrease health and cancer related risks.

Chronic Fatigue Syndrome (CFS or ME)

CFS is a disabling long-term condition with distinct physical as well as psychological components. Symptoms include short-term memory, sore throat, joint pain, muscle pain, headaches, exhaustion, poor sleep, low immunity to illness and increased thirst. There appears to be a seasonal influence on this illness, winters being the worst time. Among that group, oversleeping, daytime fatigue, carbohydrate craving and eating were indistinguishable from patients with SAD. Furthermore, seasonal CFS patients were significantly more likely to have experienced a depressive episode in the past year, usually in winter. 
Studies are being conducted to assess whether light therapy can be of use in controlling this illness. Patients trialed have shown improvements in the symptoms that are similar to SAD, and some improvement in physical symptoms such as joint pain, but this is at a very early stage, so is not to be recommended until more conclusive evidence is reached.


Bulimia is an eating disorder characterized by cycles of binge eating and purging. The eating binges often happen twice or more a week, usually in the evening. This is followed by induced vomiting, laxatives, or compulsive exercising to avoid gaining weight. Bulimics report feelings of guilt, self-loathing and feeling out of control. It is more common in women during their teenage or early adult years, about 1 to 3%, but can affect anyone. If bulimia remains untreated, it can cause serious physical and emotional problems. 
Dr. Raymond Lam of the University of British Columbia has shown that bulimia also follows a seasonal pattern, with a marked increase of bulimic episodes occurring in winter, peaking in January. In fact, about 1/3rd of bulimics also suffer from SAD, whereas anorexics experience no seasonal change in their symptoms. Dr Lam conducted a study using light therapy for bulimics, and it was found that using 30 minutes of light therapy for 2 weeks cut their binge and purge symptoms by half, whether they were found to be suffering from SAD or not. The depression also showed a marked improvement, the biggest improvement showing in those whose bulimia followed a seasonal pattern.
It was concluded that the frequent and excessive eating in bulimia upsets inner body rhythms, and that light therapy may help to regulate these rhythms, contributing to good mental and physical health.

Fatique Management

Many people in our modern hectic society work increasingly longer hours, and are expected to feel alert, energetic, and content. However fatigue is a common and often serious problem in the workplace. For instance, many lorry drivers work for 18 hours a day, and the resulting exhaustion makes crashes inevitable. For every lorry accident, an average of 5 people die along with the driver, and fatigue is the most common cause of these accidents. 
Drinking coffee as a stimulant can lead to dehydration and caffeine dependency, whereas light therapy can be used for the same benefits without the unpleasant side effects. Used regularly in combination with a sufficient amount of sleep, light supplements can regulate sleep and waking patterns, and promote alertness and attentiveness. But light supplements should never be used to replace sleep or to promote sleep deprivation, as nothing can replace a deep and sufficiently lengthy sleep.

Productivity Enhancement 

The use of good full spectrum lighting in school or the workplace, instead of conventional fluorescent lighting, has been proven to improve productivity, academic achievement and reduce rates of absenteeism.


Alzheimer is a degenerative brain disorder, in which patients are mentally confused, often agitated and have severe memory problems. 
Recently, 2 recent studies have confirmed that bright-light therapy appear to help Alzheimer patients sleep better and get less agitated. In the study, researchers from the Manchester Royal Infirmary in Manchester, England, evaluated 47 nursing home residents who all had been diagnosed with Alzheimer or other problems that lead to mental confusion, memory loss and dementia. Half of the patients received bright light therapy, the other half using only a dimmer light, each day for 2 weeks. The treatment group was shown to sleep longer and was less agitated.

It has been recommended that planning daily activities to make good use of daylight can help, such as serving breakfast facing a sunny window, or planning more outdoor activities on sunny days, as well as using light boxes or light visors.


Research has shown that fertility rates are higher at the equator, where daylight hours are longer than in far northern latitudes and that fertility rates are lower among the blind compared to those who have their sight. Women with longer or irregular cycles have higher infertility rates than those with shorter and more regular cycles. About 1 of 25 women in North America have cycles that last 35 days or more, or that vary considerably from cycle to cycle. A cycle that consistently averages about 28 days has been shown to boost a woman's odds of conceiving. 

While every woman's physiology is unique and will have different responses to different types of therapy, light has been shown to have significant effects in the regulation of the menstrual cycle. Light therapy for 15-60 minutes every morning during the premenstrual period may help relieve these symptoms. blocks the light to the Retina of the eye, should not be worn. Daily exposure to as much natural daylight as possible can be of help.