Light Therapy is useful to help us with wakefulness and guide our circadian rhythm. Our Circadian Rhythm is our sleep and wake cycle (body clock). Our Circadian rhythm is controlled and influenced by Light and Melatonin secretion from our brain. Melatonin triggers a complex cascade that allows the brain to initiate and enhance sleep. Melatonin is secreted when we no longer see substantial light stimulation to our eyes. The Circadian rhythm is very important to our body and brain, many functions of our body are controlled or optimized in our circadian rhythm. Sleep onset is influenced by circadian rhythm and sleep pressure (how sleepy we are or how long it has been since we slept).
Strong light can delay sleep onset and circadian rhythm. Light therapy can be used to control or shift our circadian rhythm either to advance (move earlier) or delay (move later). Light also inhibits melatonin secretion and sleep. Avoiding light can help our brain secrete melatonin which initiates and enhances sleep.
Light Therapy later in the day delays sleep onset and the circadian rhythm. Light Therapy early in the day enhances early wakefulness and may advance the circadian rhythm. Using light Therapy early in your day will allow you to be more of a morning person and allow getting up earlier. Using Light Therapy later in the day will push your circadian rhythm later and allow you to naturally stay up later if needed.
Light Therapy is provided by being in the close proximity to a light of a certain wavelength and intensity. Typically you want it in your field of vision. Duration is variable and prolonged exposure to bright light has uncertain side effects. Please see manufacturers label and read your manual if you are using “Light Therapy”. We recommend using a light that is at least 4,000 lux or lumens in brightness and using it for more than 30 minutes. Some effect is more if used for longer, some scientific studies use 2 hours duration of therapy. You may need to consult a Sleep Specialist to use this treatment effectively.
Light Therapy has also been shown to help in the treatment of Seasonal Affective Disorder (SAD) and depression. Light therapy may aid in treatments of Insomnia and is also used in Dementia in an attempt to keep the Circadian Rhythm from drifting to the wrong position.