What Is Light Box Therapy and How Does It Help Treat Sleep and Mood?

A man uses a light box for phototherapy to treat his sleep disorder, improving a night owl circadian rhythm and seasonal affective disorder.
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If you suffer from one of the circadian rhythm disorders, including a night owl tendency or winter blues caused by seasonal affective disorder (SAD), you may wonder: What is light box therapy? This unique treatment is sometimes called phototherapy and may be just what you need to sleep better and feel more alert during the day. It may be delivered via a light box or special light therapy glasses. How does using a light box at the proper time help to improve sleep and mood?

What Is a Light Box?

First, it is important to understand what a light box is. The light box is a specially-designed fixture that produces a soft light that is used for bright light exposure therapy. It may stand independently, but newer technology has allowed it to become integrated into light therapy glasses. With either delivery, this treatment is sometimes called phototherapy.

The light box generates a standard wavelength and amount of light. It may be full spectrum (appearing white in color, but including blue light) or it may generate only blue light. This is important because blue light is known to affect the circadian rhythm, and this impacts the timing of sleep and wakefulness.

The light should ideally have an intensity of approximately 10,000 lux to be effective. Light therapy glasses may have a lower intensity as the light is delivered more directly into the eyes, rather than being diffused into a room.

Sleep Disorders Treated with Light Box Therapy

Many problems can occur when our biological clock becomes misaligned to the natural day-night cycle. This circadian rhythm is what promotes sleep at night and alertness during the day. If this is disrupted, we may have insomnia or excessive daytime sleepiness. Various disorders can disrupt this alignment and may be effectively treated with light box therapy, including:

The timing of treatment may vary with each condition. For example, night owls may benefit most from light exposure in the morning, while those with advanced sleep phase syndrome may conversely need the phototherapy at night. It may be helpful to consult with a board-certified sleep physician to obtain proper treatment guidance. In addition, some devices may have an associated app that can provide support and some helpful instructions on how to optimize the treatment.

The Role of Light in Mood Disorders

Beyond impacts on sleep, seasonal changes in the day length may also cause difficulties with our mood. With shorter days and longer nights, starting one’s day before natural light begins with sunrise may lead to symptoms of winter blues, depression, or seasonal affective disorder (SAD). Darkness at night after work may also impact our activity levels and mood.

Exposure to bright light in the morning may help to reset our biological clocks, but without it we may feel prolonged sleepiness that lasts late into the morning. Phototherapy may alleviate mood disorders that are worsened by seasonal changes in light exposure.

Symptoms Responsive to Light Box Therapy

There are certain symptoms that might be expected to be more responsive to light box therapy. These symptoms include:

  • Insomnia
  • Excessive morning sleepiness or hypersomnia
  • Winter or seasonal depression
  • Lethargy

The response to treatment varies. Benefits may be noted in the first few weeks, but consistency is key. Try to use the therapy daily at the time prescribed. Inconsistent use may impact the effectiveness of the treatment.

Using Sunlight as Treatment Instead

When possible, try to get natural sunlight exposure instead. The sun provides up to 100,000 lux of full-spectrum light and this will have a stronger impact on the circadian timing. Do not wear sunglasses or a hat or visor. Let the sun shine on your face, but do not stare directly at it to avoid damage to your eyes.

A Word From Verywell

If you feel that you have symptoms or a condition that might be responsive to light box phototherapy, you may wish to consult with your physician before selecting a light box. The guidance provided may allow you to effectively determine the timing and duration of your treatment. If you continue to struggle, it may be helpful to consult with a sleep physician or psychiatrist for further assistance.

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Article Sources
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