This newspaper reports that staying up late scrolling through your phone with the desk lamp on, leaving bedroom nightlights on all night, and urban light pollution penetrating through curtains… these commonplace scenes in modern life may be quietly eroding your cardiovascular health. Recently, Flinders University in Australia released the largest study to date on light exposure and cardiovascular health. By analyzing over 13 million hours of light monitoring data from 88,905 people aged 40 and over, the study confirmed that strong nighttime light exposure significantly increases the risk of heart failure and heart attacks, while sufficient sunlight can have a protective effect on the cardiovascular system. The research team used lux as a standard for measuring light intensity, clearly defining the light thresholds for different environments: the light intensity of a dark night sky is less than 0.01 lux, while a well-lit indoor environment exceeds 100 lux. Data analysis showed that compared to those with the least nighttime light exposure, participants exposed to the highest intensity nighttime light (median above 105.3 lux, in the 91st to 100th percentiles) had a 56% higher risk of heart failure and a 47% increased risk of heart attack. Notably, this health threat was more pronounced in younger people and women, suggesting that these groups may be more sensitive to circadian rhythm disruptions. "The core harm of nighttime light exposure lies in disrupting the body's natural sleep rhythm," explained the study's lead researcher. The suprachiasmatic nucleus of the hypothalamus, the core of the body's "biological clock," regulates melatonin secretion through the retina's perception of light changes. Strong nighttime light inhibits melatonin production, leading to difficulty maintaining sleep and fragmented sleep. This rhythm disruption itself is an independent risk factor for cardiovascular disease. Previous studies have shown that abnormal sleep rhythms activate the sympathetic nervous system, leading to increased heart rate and vasoconstriction, which can induce blood pressure fluctuations and increased myocardial load in the long term. The study also uncovered a set of positive findings: adequate sunlight exposure can protect cardiovascular health. Without adjusting lifestyle factors such as diet and exercise, regular sunlight exposure can reduce the risk of coronary artery disease, heart failure, and stroke by 13% to 28%. This finding further confirms the importance of the natural circadian rhythm of "working at sunrise and resting at sunset" for health. Based on the research results, the research team offered several practical recommendations: the public should try to avoid exposure to strong light during sleep at night, and bedroom lighting intensity should be kept at a low level, prioritizing low-irritation light sources such as amber; reduce the use of electronic devices 1-2 hours before bedtime to avoid blue light inhibiting melatonin secretion; and appropriately increase outdoor sunlight exposure during the day, especially during work breaks. Furthermore, the researchers called on relevant departments to conduct further specialized research and develop healthy usage guidelines for home, hospital, and urban public lighting to reduce the potential threats of light pollution to cardiovascular health from an environmental perspective. "This study provides a completely new perspective on cardiovascular disease prevention," commented an industry expert. The expert pointed out that reducing nighttime light exposure, as a low-cost and easy-to-implement intervention, has the potential to become an important supplement to traditional preventative measures. Future research should incorporate more clinical data to optimize light exposure health standards, helping the public balance convenience and health in modern life.