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Exposure to Artificial Blue Light Can Cause Sleep Problems


Sunlight is good. Scientists have long known that natural sunlight is beneficial for all living things — including humans. Sunlight provides essential amounts of Vitamin D, has a positive influence on many of our bodies’ hormones and chemical processes, and it helps regulate our circadian rhythms. Circadian rhythms are changes (physical, mental, and behavioral) that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment. They are found in most living things, including animals, plants, and many tiny microbes, which play an important role in governing our sleep patterns.

Unfortunately, all light is not created equal. In fact, there is growing scientific evidence that artificial “blue” light emitted by laptops, smart phones, and other electronic devices, especially at night, can be detrimental to good sleep, and our overall health. Until the advent of artificial light a little more than a century ago, the sun was the major source of light, and people spent their evenings in near darkness. They did have campfires, candles, oil lamps, and other types of light based on heat/fire produce primarily red/yellow light, which has little or no negative impact on human sleep. Today, however, many people spend their evening hours exposed to large amounts of artificial blue light, which can have a serious adverse impact on the body’s biological clock — the circadian rhythm. Sleep suffers. Worse, research shows that it may contribute to the causation of cancer, diabetes, depression, heart disease, obesity, and other serious health issues.

Everyone has slightly different circadian rhythms, but the average length is 24 hours, and on-quarter hours. The circadian rhythm of people who stay up late is slightly longer, while the rhythms of those who go to bed earlier fall short of 24 hours. Exposure to sunlight in the daytime keeps a person’s internal clock aligned with the environment’s light/dark cycle. Exposure to artificial blue light at night disrupts our internal clock, and makes it harder for us to sleep. Study after study has linked exposure to blue light at night to breast and prostate cancer, diabetes, heart disease, and obesity. We don’t know all the reasons why exposure to blue light is detrimental to our health; we do know, however, that exposure to artificial light at night suppresses the production of melatonin, a hormone that significantly influences the human body’s circadian rhythm. Many sleep scientists believe exposure to artificial light in the evenings may keep brain serotonin levels elevated by preventing the conversion of serotonin to melatonin, and without it, we won’t feel sleepy.

If you have trouble going to sleep, staying asleep, or you don’t feel well-rested in the mornings when you wake, talk to your physician. They may recommend you undergo a sleep study to determine if there is a medical reason for the problem, and take appropriate actions to address it. Call the Hopedale Medical Complex Sleep Center for more information on a sleep study at 309-449-4757, or visit

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