Block out all light at night when you sleep: It’s important for your health, study finds

If your blinds or curtains aren’t blocking out the moonlight or street lights at night, you might want to consider replacing them with a block-out option – for the sake of your health. The same applies to artificial light, such as from a TV or bedside lamp. 

According to a new study, being exposed to even moderate ambient lighting during nighttime sleep can harm your cardiovascular function and increase your insulin resistance the following morning. 

Senior study author, Dr Phyllis Zee, chief of sleep medicine at Northwestern University Feinberg School of Medicine, explained: "The results from this study demonstrate that just a single night of exposure to moderate room lighting during sleep can impair glucose and cardiovascular regulation, which are risk factors for heart disease, diabetes, and metabolic syndrome."