INTRODUCTION Prevalence of insomnia is between 10% and 20%, out of those 50% are chronic cases. It is a common condition characterized with difficulty initiating or maintaining sleep, and symptoms such as irritability or fatigue during wakefulness. Light pollution has become a global problem in recent years and its connection to disruption of sleeping patterns and circadian rhythm in animals and people has been proven and reported. AIMS The aim of this study was to determine the effects of light pollution on Croatian students’ sleeping habits. PARTICIPANTS AND METHODS This on-line, anonymous questionnaire study was done during January and February 2019 by the use of specially designed questionnaire which contained questions regarding the demographic data, sleeping habits and questions about light pollution. RESULTS There was a total of 202 participants, mean age 21,8 years (range 18 to 31 years). Out of them 79.2% (160/202) were females. According to the working status 70.8% (143/202) were students who did not work, 25.7% (52/202) worked one shift and 3.5% (7/202) worked night shifts or more different shifts. Most of them, 76.7% (155/202) fell asleep in less than 30 minutes, 20.8% (42/202) fell asleep 60-90 minutes, and 2.5% (5/202) fell asleep after 90 minutes. Most of the participants 94.1% (190/202) didn’t plan on moving because of light pollution. There was a statistically significant difference in quality of sleep and amount of light around the household (p<0.001). Conclusion: Light pollution affects sleeping habits of Croatian students and is becoming a larger problem every day
