Insomnia is the inability to get adequate sleep. There are actually two types of insomnia, difficulty falling asleep and difficulty staying asleep. Cancer patients can experience insomnia during chemotherapy treatments because:
- The chemotherapy session leaves the patient feeling tired and consequently they need to nap after the session. However, this interferes with their ability to sleep at night.
- Certain drugs that are prescribed to treat the nausea associated with chemotherapy can make the patient feel full of energy and this can interfere with the ability to sleep.
These drugs interrupt the circadian rhythm, which is the body’s internal clock that tells it when it is time for sleeping and time to be awake. Light Therapy, sometimes called Bright Light Therapy, is being used to treat the inability to sleep as a result of the circadian rhythm having been altered.
How Does Light Therapy Work?
The body’s internal clock is usually set by exposure to sunlight.
However, in this form of therapy, a bright, artificial light source is
used in place of sunlight to re-set the internal clock.
Light Therapy exposes the patient’s eyes to very strong but safe amounts of light for a pre-set length of time. The goal is change the altered settings of the internal clock back to the right time so that the patient can once again experience a healthy sleep pattern.
There are four methods used for Light Therapy:
- Light box- This is the tool used most often in Light Therapy. This is a box-shaped apparatus that contains several tubes that give off extremely bright light. It is placed on top of a table, and the patient is seated about 18 to 24 inches away from the box, and is asked to face in the direction of it. During the treatment session, the patient can read or perform other activities that can be done while seated. The idea is to allow the eyes to take in the light, which will then be used to regulate the internal clock. The current models of light boxes give off 10,000 lux of light. A lux is a measurement of how much light falls on the eye. This high level of light exposure means that a treatment session usually lasts between 15 to 30 minutes.
- Desk lamp- This works in the same way as the light box, but it is designed to look like a normal desk lamp.
- Light visor- This looks like a visor worn while playing sports, and it is worn in the same way for treatment. It allows the patient to move around during the session.
- Dawn simulator- The patient is placed in a darkened room and lights are gradually brightened over a period of time to simulate the sun rising at daybreak.
How Did Light Therapy Originate?
Dr. Niels Finsen is recognized as the father of modern light therapy. He developed the first artificial light source to treat lupus vulgaris, a painful skin condition in which lesions develop on parts of the face.
Is Light Therapy Safe?
Light Therapy is considered safe as long as the session is conducted within the prescribed time limit and using the recommended light intensity limit. However, it can produce the following side effects:
- Eye irritation
- Skin dryness