Light Therapy

Patients undergoing light therapy – also known as bright light treatment, ultraviolet phototherapy, photodynamic therapy, and chromatotherapy – are generally treated with the use of light either from the visible spectrum or ultraviolet rays.  Some practitioners claim it is effective for many different conditions.  Some forms of light therapy – light boxes, ultraviolet (UV) light therapy, and photodynamic therapy – are used in conventional medicine. There is no research to support its use in the cure of cancer or other illnesses.

Light therapy may be administered by professionals, but is sometimes prescribed for home use. It takes on many different forms. Light boxes simulate the wavelengths of sunlight and are used for a recommended length of time and frequency.  Some of these devices may employ colored lights. When ultraviolet light is used, eyes and unaffected skin are protected. These treatments are purported to relieve a variety of conditions including high blood pressure, insomnia, PMS, migraines, and hyperactivity.  Some have claimed that UV light is able to kill “toxins” in the body, including bacteria, viruses, and cancer cells.

Medical Uses

UV light is even used to irradiate the blood.  During a procedure called photopheresis, blood is removed from the body and treated with chemicals to make it more light-sensitive before it is exposed to UV light. After treatment, it is returned to the bloodstream.  This process has been approved by the FDA to treat T-cell lymphoma involving the skin, and it may also be used to treat organ transplant or immune disorder patients.

Despite the fact that light alone has not been shown to kill cancer, different types of light have been shown to have a variety of medical uses.  Light box therapy can help patients suffering with seasonal affective disorder or insomnia by simulating sunlight.  UV light is used to treat psoriasis and other skin disorders.  Even chromatotherapy, or treatment with colored light, has been effective in helping infants with excessive bilirubin in their blood break down and secrete the substance.

Therapy with visible light is generally considered safe, though this type of treatment should not be confused with tanning beds or sun lamps, which can produce dangerously high levels of UV radiation.  Excessive exposure to UV radiation, even through carefully monitored treatments, actually raises risk for a variety of skin conditions, including cancer.


American Cancer Society