Introduction:
Evening exposure to blue light from digital devices has been associated with sleep disruption, reduced life satisfaction, and problematic internet use in adolescents, yet few studies have investigated these factors together in a single population.

Aim:
To examine the relationships between pre-sleep screen exposure, sleep quality, life satisfaction, and internet use behaviors, and to explore factors associated with poor sleep quality among high school students.

Material and methods:
A cross-sectional study was conducted in May 2025 with 364 students (grades preparatory to 11) from a private high school in Istanbul. Data were collected via an online survey including the Pittsburgh Sleep Quality Index (PSQI), Young Internet Addiction Test–Short Form (YIAT-SF), and the Satisfaction with Life Scale (SWLS). Descriptive statistics, Spearman correlations, and binary logistic regression were performed.

Results and discussion:
Poor sleep quality was observed in 83.0% of participants, and 48.1% demonstrated borderline or risky internet use. PSQI was positively correlated with YIAT-SF (r = 0.401, p < 0.001) and negatively with SWLS (r = −0.254, p < 0.01). Logistic regression analysis indicated that higher YIAT-SF scores (OR = 1.067, p = 0.010) and screen exposure in the last hour before sleep (OR = 5.487, p < 0.001) were significantly associated with poor sleep quality.

Conclusions:
Problematic internet use and evening screen exposure are significantly associated with poor sleep quality. School-based initiatives promoting digital hygiene and sleep education may contribute to mitigating the adverse effects of technology on adolescent well-being.