How Does Artificial Light Affect SleepHave you ever wondered why people sleep with the lights off? Or why you can be extremely tired until you start watching TV or playing on your phone. You probably don't think that light has a very big effect on sleep. But maybe light, or artificial light, has a more serious effect on sleep than you think. According to some online resources, this causes the suppression of a sleep-inducing hormone and disrupts our entire sleep cycle. It can even be the main cause of sleep disorders. A resource from Harvard Medical School states that our internal clock is regulated by light. There are cells in our eyes that detect light and tell our brain when it's night or day, this way we know when to sleep. But since the invention of the light bulb, we are exposed to light later in the day, when there is usually no light. For this reason, our eyes tell us that the time is earlier than it actually is, so our body prefers to sleep later. So, light causes our internal clock to reset and makes us prefer different sleep times. According to Britannica, a person's sleep and wake cycle, called the circadian rhythm, is regulated by the production of melatonin. Melatonin is a hormone that makes us tired. This causes changes that promote sleep, such as a decrease in body temperature and respiratory rate. Melatonin production is influenced by light. The retina detects light and the cells in the retina send signals to the brain regarding light stature. Then, depending on the amount of light present, melatonin increases its production or is limited. More light equals limited melatonin, which makes us awake, and dim light equals more melatonin, so we fall asleep. This is how the light changes... middle of paper ......sleep, seven people, all of whom were using some sort of electronic device in the hour before sleep, and had or sometimes struggled to sleep . This therefore supports the idea that light suppresses melatonin and causes loss of sleep. Of the three who slept less than eight hours, two of them sometimes or did not have difficulty falling asleep. The other used electronic devices in the hour before bed and had trouble falling asleep. I would say that the investigation supports my conclusion. Whenever people used electronic devices in the hour before bed, they had trouble falling asleep and typically slept less than eight hours. Additionally, when they didn't use electronic devices in the hour before bed, they generally had no trouble falling asleep and slept for more than eight hours. So I would say that this supports my conclusion..