Negative effects of artificial lighting: Artificial lighting from nightlights, TV screens, and computer screens while you sleep can have a negative impact on your health and mood. In a study from Ohio State University Medical Center, hamsters with chronic exposure to dim light at night showed signs of depression within only a few weeks. The American Medical Association has reported that artificial lighting disrupts circadian rhythms and alter the body’s normal hormonal responses. The release of melatonin (a hormone thought to fight tumor growth and cancers) has been shown to be suppressed by exposure to light at night. Changes in circadian rhythms can impact obesity, diabetes, and reproductive problems. With this in mind, turn off the lights at night and get a good night’s sleep!