About Our Practice

Light therapy is a treatment used for people who suffer from circadian rhythm sleep disorders.  Your body has an internal clock that tells it when it is time to be asleep and when it is time to be awake.

Circadian rhythms make you feel sleepy or alert at regular times every day.  Some people have a circadian rhythm sleep disorder.  This causes their natural sleep time to overlap with regular wake activities, such as work or school.

Among other factors, your clock is "set" by your exposure to bright light, such as sunlight.  Exposure to bright light or "light therapy" is one method used to treat people with a circadian rhythm sleep disorder.

The goal for treating patients who have a circadian rhythm problems is to combine a healthy sleep pattern with an internal clock that is set at the right time.  This will allow them to enjoy the benefits of good sleep.

Light therapy can help someone "reset" a clock that is off.  Regular sleep patterns help to keep the clock set at the new time.  Light therapy is only part of a treatment plan that should be guided by a doctor who is familiar with sleep disorders.

Light therapy is used to expose your eyes to intense but safe amounts of light for a specific and regular length of time.  In many places, sunlight is not available at the proper time to be used as treatment.

Artificial light may be used to affect the body clock in the same way that sunlight does.  New advances continue to be made in this field.  Currently, products used for light therapy fit into four basic groups:

Light Box                                                                                       

This is the most common tool used in light therapy.  The box houses several tubes that produce extremely bright light.  It sits on top of a table or desk, and plugs into the wall.

During a treatment session you have to keep within a certain distance of the box.  Usually, you will be about 18-24 inches away from it.  You are not required to look directly into the light.  Instead, you simply face in the direction of the box.

You are able to do other activities during the session.  Ideally, you would work on papers or read something that is in the area being lit up.  This will allow the light to be received by your eyes.  Your body takes in this information and uses it to regulate the rhythms that control when you sleep and when you wake.

Earlier models of light boxes put out 2,500 to 5,000 lux of light.  Lux is a measure of how much light falls on your eyes.  These sessions could take two or three hours.  How, many boxes produce 10,000 lux of light.  This allows sessions to take as little as 15-30 minutes.

More than one session may be needed each day.  It depends upon your body, your need, and the strength of light being used.  The key is to use the light at the right time of day and for the right amount of time.  This is based upon the sleep disorder you want to correct.

New models are also safer, protecting you from harmful UV rays.  Some models are now focusing on a specific bandwidth of light.  Light boxes can be purchased in a variety of makes and models.  Some are now being made much smaller so they are easier to take with you.

Desk Lamp

This serves the same purpose as a light box, but it is made to look like a normal lamp.  It blends in better when used in an office setting.

Light Visor

This is a light source worn on your head, that hangs over your eyes.  It looks much like a tennis visor.  It is made so you can move around during sessions.  The strength of visor lights also varies from 3,000 to 10,000 lux.

Dawn Simulator

These lights gradually make a dark room brighter over a set period of time.  This is meant to mimic the sunrise.  Some people may find this helps them wake up in the morning.  Models may also slowly dim to copy a sunset.

Possible Side Effects of Bright Light Therapy?

Light therapy has a good record of safety.  It does not seem to produce any major side effects.  Light therapy should always be used within the proper limits for intensity and time.  Minor side effects may include:

Eye irritation and dryness

Headache

Nausea

Dryness of skin

To reduce these side effects, begin the light therapy very slowly.  Give your body time to get used to it.  The use of a humidifier can also help with irritations caused by dryness.  Talk to your doctor or a sleep specialist before beginning use.

04/2008 Content reviewed by Richard Parisi, MD