A study published in JAMA Network Open suggests that being exposed to light during the night may increase the risk of cardiovascular diseases, such as heart failure, heart attack, and stroke. The research followed nearly 89,000 adults over more than nine years. Participants wore sensors that recorded their exposure to light during nighttime hours. The findings showed that the more light individuals were exposed to between midnight and 6 a.m., the higher their risk of these health issues became. For those exposed to the most light, the risk of heart attack or stroke increased by up to 56%. Experts believe that the negative effects of nighttime light exposure may be linked to disruptions in the circadian rhythm. This is the body's internal clock that controls when we feel awake or sleepy. Artificial light, such as from phones or lights, can trick the brain into thinking it is still daytime. This can lead to poor-quality sleep, even if the amount of sleep appears adequate. Poor sleep is already known to be a risk factor for heart-related conditions. During deep sleep, the body repairs itself. If this sleep is broken or reduced, it can increase stress and anxiety, and activate the body's "fight or flight" response, which can strain the heart. Dr. Ehimen Aneni, a professor of cardiovascular medicine at Yale, noted that "even seven or eight hours of sleep are not enough if their quality is poor." Women, in particular, appear to be more vulnerable to these disruptions than men. Sources of nighttime light are common in daily life, such as street lamps, smartphone screens, nightlights, and televisions. Although the study does not specify the type of light, it encourages people to reconsider their nighttime habits before going to bed. Suggestions for better sleep and cardiovascular health include turning off screens, using blackout curtains, and sleeping in a completely dark room. These steps may help improve the quality of sleep and reduce long-term risks to heart health.