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Light therapy


Also listed as: Bioptron, Phototherapy
Related terms
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Related Terms
  • Acne, bili blanket, BIOPTRON, delayed sleep phase syndrome, DSPS, light therapy, neonatal jaundice, photomedicine, phototherapy, psoriasis, SAD, seasonal affective disorder.

  • Light therapy, also known as phototherapy, is the use of a specialized machine to emit only a specific wavelength of the light spectrum. Light therapy consists of exposure to specific wavelengths of light using lasers, LEDs, fluorescent lamps, dichroic lamps or very bright, full-spectrum light, for a prescribed amount of time. Each wavelength in the light spectrum is said to possess specific qualities. Advocates claim that each wavelength may assist a person who is diagnosed with a particular condition experience relief. Light therapy machines offer more of a particularly useful wavelength than would be available by exposure to the sun.
  • The use of light therapy in medicine has a long history. Although phototherapy had no scientific basis at the time, natural sunlight was used for medical treatments in ancient Egypt and Greece. Later, Roman and Arab physicians introduced light therapy into general medical use. The Danish physician Niels Ryberg Finsen founded modern light therapy about 100 years ago. In 1903, he was awarded with the Nobel Prize in medicine for his achievements with light therapy. Finsen created the first device to generate technically synthesized sunlight and achieved outstanding results in the treatment of patients suffering from a special type of skin tuberculosis.
  • Today it is known that the human organism transforms light into electrochemical energy, which activates a chain of biochemical reactions within cells, stimulating metabolism and reinforcing the immune response of the entire human body. The human response to light therapy is more complicated. Natural sunlight does not offer wavelengths of useful light in strong enough concentrations.
  • Light therapy is a first line treatment for neonatal jaundice. It is also very popular as a treatment for seasonal affective disorder (SAD). The Food and Drug Administration (FDA) has recently approved a special type of light therapy machine to treat psoriasis. Light therapy is approved by major medical organizations for the treatment of these conditions. Light therapy is sometimes used to treat other difficult conditions, including chronic wounds or skin problems, burns, chronic rheumatic conditions, acute joint pains, acute sports injuries, post-operative scar healing, hair loss and dandruff, periodontitis, and gynecological disorders.
  • In recent years, an increasing number of individuals have used light therapy to treat delayed sleep phase syndrome, and acne. The medical community is currently conducting clinical trials of light therapy for these purposes.

Theory / Evidence
  • Light therapy is said to have developed because simply exposing the skin to normal sunlight did not provide enough of the desired results. Sunlight contains many different types of light. Each of these types puts out a particular wavelength, and occupies a specific spectrum of light. Light therapy machines concentrate the wavelength that is thought to be beneficial to a person with a particular diagnosis.
  • There are clear advantages in using technically synthesized sunrays, for example, the parameters of intensity and the emitted light spectrum are controllable, and therefore reproducible.
  • Acne: Advocates claim that phototherapy decreases populations of bacteria and enzymes, which are usually overabundant during the formation of acne. However, evidence is lacking in this area.
  • Delayed sleep phase syndrome (DSPS): The way that light therapy might assist a patient in establishing and maintaining a normal sleep/wake cycle is unknown. However, it is theorized that the bright light provides an extra biological cue that aids the body in awakening.
  • Neonatal jaundice: In newborns with jaundice, research has shown the efficacy of light therapy to assist the liver in lowering the levels of bilirubin in the blood.
  • Psoriasis: The affected area of skin is exposed to UV light in order to activate a part of the body's immune system. The light kills T cells. The decrease of T cells in the body slows the process of inflammation and causes the loss of skin cells to slow down.
  • Seasonal affective disorder (SAD): It is hypothesized that the length of exposure to sunlight affects the brain's production of serotonin, a chemical that influences mood. However, light therapy's exact mechanism in the treatment of depression is unknown.


Author information
  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (

  1. American Academy of Dermatology. Last accessed June 16, 2006.
  2. American Academy of Family Physicians. Last accessed June 16, 2006.
  3. American Liver Foundation. Last accessed June 16, 2006.
  4. American Psychological Association. Last accessed June 16, 2006.
  5. Food and Drug Administration. Last accessed June 16, 2006.
  6. Lam RW, Levitt AJ, Levitan RD, et al. The Can-SAD study: a randomized controlled trial of the effectiveness of light therapy and fluoxetine in patients with winter seasonal affective disorder. Am J Psychiatry. 2006 May;163(5):805-12.
  7. National Psoriasis Foundation. Last accessed June 16, 2006.
  8. Stasinopoulos D, Stasinopoulos I. Comparison of effects of Cyriax physiotherapy, a supervised exercise programme and polarized polychromatic non-coherent light (Bioptron light) for the treatment of lateral epicondylitis. Clin Rehabil. 2006 Jan;20(1):12-23.
  9. Stasinopoulos D, Stasinopoulos I, Johnson MI. Treatment of carpal tunnel syndrome with polarized polychromatic noncoherent light (Bioptron light): a preliminary, prospective, open clinical trial. Photomed Laser Surg. 2005 Apr;23(2):225-8.
  10. World Health Organization: Problems with the Neonate and Young Infant. 2 June 2006.

  • Patients may need to wear special protective clothing to prevent sensitive areas, such as the eyes and genitals, from being painfully burned in the course of light therapy.
  • Medical insurance reimburses the use of light therapy for neonatal jaundice, and some insurance plans will cover light therapy for SAD or psoriasis.
  • Acne: The exposure to a phototherapy device varies, and no professional associations have established a protocol for its use. The individual typically spends at least 30 minutes in front of a light therapy machine every day.
  • Delayed sleep phase syndrome (DSPS): For this condition, the patient turns on the light upon waking for 30 to 90 minutes. If the patient is attempting to establish a 24-hour sleep/wake cycle, they might turn on the light at the time they are supposed to awake in the morning.
  • Neonatal jaundice: A special blue light, also called a "bili blanket," is installed in the newborn's crib within a week of birth. The child wears only a diaper in order to maximize skin exposure, and the perimeter of the crib is lined with protective material. The blue light stays over the child's crib until their skin returns to a normal color. Phototherapy is the frontline treatment for the most popular of newborn conditions.
  • Psoriasis: For scalp psoriasis, patients may be prescribed a handheld light therapy box for use at home. The patient steps into a fully lighted box, which is about the size of a telephone booth. Usually, however, the patient makes three to five visits per week to the doctor's office. The duration of treatment may last from several weeks to several months. Once the desired effects are achieved, the patient must make follow up appointments every month. Some patients may need to take a medication to sensitize their body to the light, or use a higher intensity of light for the treatment to be effective. One phototherapy machine to treat psoriasis is approved by the FDA
  • Seasonal affective disorder (SAD): The patient purchases a specialized lamp or light box. Starting in the fall, the patient sits in front of the light box for at least 30 minutes per day. Phototherapy is one of the primary treatment options for non-suicidal individuals with SAD.

Copyright © 2011 Natural Standard (

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

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