Circadian Research by Mark Rea, PhD, Professor of Cognitive Science and Director. Lighting Research Center, Rensselaer Polytechnic Institute presented at the International Conference on Light and Vision Niagara Falls, Ontario, Canada
Dr. Rea presented a very interesting paper on the effects of light during the day on circadian rhythm and melatonin production at night. I previously wrote about the importance of getting a good night sleep in a totally dark room http://www.healingtheeye.com/melatonin.html
His research indicates that if you are not exposed to enough light during the day it can affect your sleep cycle and your health. His research revealed that blue light at 470 nm (the color of the blue sky) had the greatest impact during the day. He conducted a study at a nursing home looking at the affects of blue light on the sleep cycle. A group of seniors looked at blue LED lights for one hour in the evening after the sun set. Their sleep was checked every 2 hours during the night. The group that looked at the blue light were found to be sleeping 90% of time and the control group (no blue light) only 65% of the time.
This study has amazing implications. We need to expose ourselves to more bright natural light during the day to keep the circadian rhythm of the body functioning. A proper circadian rhythm according to Dr. Rea not only helps us get a good night sleep but he showed several studies that indicate it will also reduce the incidence of cancer and chronic disease.