Here are the highlights from an interview with Dr. Michael Terman who is the Director of the Center for Light Treatments and Biological Rhythms at Columbia University Medical Center.
The rising of the sun speaks directly to your internal clock. This occurs because the sunlight stimulates the retina of your eye which sends a signal to the base of your brain. The outer clock is the solar clock or rather the clock that runs the world. In the winter there is less sun and some people are more prone to get the blues or depression because of the shift of sunrise. If you use artificial light when you wake up and before you go to work then it tricks the mind and body into feeling better by adjusting your inner clock. The best amount of light is the level of light you would get walking on the beach for 40 minutes after sunrise. The best lit architectural spaces is 600 lux as opposed to the 10,000 lux you would receive during that walk on the beach.
For those who are having insomnia they can try light therapy in the morning which is at the end of your internal night clock. The timing of the lights is critical. We each have an internal night and we have an external night. Each of our internal nights can differ by hours so you need to find out where your internal clock is sitting. You can take a test at Center for Environmental Therapeutics. Look for morningness and eveningness questionnaire under self-assesstment tools click the circadian rhythm. This website will give you information about light therapy as well as your personal internal clock.
The hormone melatonin is a gauge for sleep time. Your body naturally begins making melatonin about 2 hours before it is ready for bed. According to Dr. Terman taking an over the counter melatonin pill before bed is mostly useless because your body is already producing it. Their research shows it is better to take a much lower dose hours before bed to try and signal you brain to get ready for bed or move your internal clock.
To handle jet lag when going east he suggest protecting your eyes from the light by wearing dark sunglasses or special filtering glasses when you land until noon and for the first few days until noon. Jet lag will be worse if you step right off the plane into the bright Paris sunlight straight from the plane. Filtering the light with glasses the first few days will reduce the disruptive symptoms of jet lag.
Dr. Terman also suggest we are not lighting up our homes enough in the morning and have too much lighting in the evening from TVs, computer screens, and the such. We need to be dimming everything as the evening approaches and turning up the lights in the morning. He suggest this for kids before they become teenagers when the internal clock truly does change and sleep patterns and school start times can be very difficult. So crank those lights while they are brushing those teeth. He also addresses the blue light theory from TVs and receivers which interferes with the body’s function of making melatonin at night. There are amber blue block glasses which allow you to see clearly but filter out the blue light component so your body’s melatonin production remains on schedule.
The light therapy has been used in research to address depression and bi-polar disorder ONLY when in the depressed state. This would require a doctor’s care. Light therapy has shown to have positive effects on dementia, depression during pregnancy, and eating disorders.