Light Therapy for Circadian Rhythm Disorder

Updated on December 17, 2021
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Sleeping in the dark might help you to sleep better, but did you know that light – when used properly – can also help you sleep better? 

The relationship between sleep and light is more powerful than you may believe. Certain people who are suffering from circadian rhythm sleep disorders or insomnia may benefit from light therapy sessions.

Read on to know more about these light therapies, their mechanism, and the disorders they can aid to treat.

What’s Light Therapy?

Light treatment is a sort of therapy that uses artificial light to treat various health issues. During a light treatment session, the patient sits or even lies in front of customized equipment called a light therapy box that generates strong light that mimics the light of the sun. Alternative terms for light therapy include bright light therapy, circadian light therapy, and phototherapy.

Patients suffering from insomnia, circadian rhythm sleep problems, or certain types of depression may benefit from light treatment. 

Doctors usually suggest the use of this therapy if the patient suffers from:

  • Affective seasonal disorder (SAD)
  • Circadian rhythm syndrome

According to various research, these conditions can be treated with the regular use of light therapy. 

The Science Behind Sleep and Light Therapy

Your circadian rhythm controls how tired you feel, how attentive you are, how hungry you are, and many other functions that you may not even be aware of. 

The circadian rhythm is so-called because it roughly corresponds to the sun’s 24-hour cycle.  By exposing your eyes to sunlight-like light, light therapy assists in realigning the circadian rhythm with the sun’s rhythms. This, as a result, will make you feel fatigued when the sun sets in the evening and more awake as the sun rises in the morning.

Specifically, during a light treatment session, the light due to this therapy is perceived by the retinal cells in your eyes, influencing certain neurotransmitters in your brain. 

Melatonin and serotonin are the two hormones that regulate your sleep-wake cycle. The sense of light delays the creation of melatonin in your brain, thereby waking you and also elevating your mood.

Light therapy is most beneficial when used regularly in the morning since people who suffer from the circadian rhythm or depression-related sleep problems are what experts refer to as “phase-delayed.” 

This is why it’s also known as an internal body clock that operates “behind” a regular circadian rhythm, causing a person to naturally feel sleepy and awaken later than usual.

What Issues Can Light Therapy Assist With?

Insomnia, circadian rhythm sleep problems, seasonal affective disorder, depression, and many other issues can be cured with this treatment.


Insomnia is a term that refers to persistent difficulties falling asleep, remaining asleep, or getting adequate sleep. Insomnia can occur on its own or in conjunction with another health condition such as depression or anxiety, Alzheimer’s disease or dementia, or another mental health illness. In many cases, light treatment can be useful in treating insomnia.

Circadian Rhythm Disorder

Certain individuals suffer from insomnia because of circadian rhythm sleep disturbance. These sleep problems may arise naturally, as in extreme night owls, or maybe due to overnight shifts. One of the principal treatments for these illnesses is light therapy.

Jet Lag

Jet lag happens when your body crosses time zones and the circadian rhythm stays in line with your previous location. You may feel sleepy or even dizzy in the middle of the day or even awake at 3 a.m. until it catches up to your new location. 

Spending some time outside might be a highly effective cure for jet lag, as it assists your biological clock in resetting to the sun. Although light treatment may assist in treating this in cases of severe jet lag caused by traveling across multiple time zones.

Seasonal Affective Disorder (SAD)

SAD is a kind of depression that occurs throughout the winter season. It occurs in the fall and winter for the majority of people. 

SAD is triggered by seasonal fluctuations in the sunshine, and its strength varies according to one’s distance from the earth’s equator. Sleep problems are frequently associated with trouble falling asleep and the tendency to feel drowsy despite ten or more hours of sleep every night.

Additionally, light therapy can help avoid the onset of SAD symptoms. People with SAD use light treatment during the winter to reduce their chances of being affected by SAD.


People who suffer from non-seasonal depression are also prone to sleep problems, such as insomnia, and also tend to develop circadian rhythm disorders.  

While the evidence is not definitive, the light treatment appears to benefit patients who suffer from non-seasonal depression as well. 

Light treatment alone may be therapeutic for these people, however, it is generally more effective when combined with antidepressants.

Bottom Line

In general, light treatment is believed to be quite safe. Although some people have adverse reactions to light treatment, such as headache, eye strain, hyperactivity, and skin irritation.

Occasionally, the adverse effects might last a few days. Still consult your doctor if you face severe issues. They may propose adjusting the duration, the device, or even your sitting posture during these therapy sessions. 

The Editorial Team at Healthcare Business Today is made up of skilled healthcare writers and experts, led by our managing editor, Daniel Casciato, who has over 25 years of experience in healthcare writing. Since 1998, we have produced compelling and informative content for numerous publications, establishing ourselves as a trusted resource for health and wellness information. We offer readers access to fresh health, medicine, science, and technology developments and the latest in patient news, emphasizing how these developments affect our lives.